With the expectation from Sharks management that Ehrhoff would join their organization either with the NHL club or in the AHL, he was signed to a contract on 22 June 2003.
Ehrhoff made his NHL debut on 9 October 2003, against the Edmonton Oilers.
He recorded his first point, an assist, on 15 November against the Toronto Maple Leafs.
Later that month, he scored his first NHL goal, a game winner against Michael Leighton in a 3–2 win against the Chicago Blackhawks on 26 November.
Ehrhoff was selected to play in the 2004 NHL YoungStars Game, along with teammate Jonathan Cheechoo.
Aftering helping the Western Conference YoungStars to a 7–3 win over the East, Ehrhoff also did colour commentary during the All-Star Game for a German telecast.

Ehrhoff was often a healthy scratch with the Sharks during his rookie season and spent time with their AHL affiliate, the Cleveland Barons.
In 41 games with the Sharks during the 2003–04 season, Ehrhoff recorded 12 points in 41 games, while in the 27 games he played for the Barons, he notched 14 points.
He began asserting himself early in his NHL career as an excellent skater with offensive capabilities.
Ehrhoff then played a full season with the Barons in 2004–05 due to the NHL lockout, tallying 35 points in 79 games.
He was chosen to represent PlanetUSA in the 2005 AHL All-Star Game in Manchester, New Hampshire.

Returning to the Sharks in 2005–06, Ehrhoff recorded a 23-point campaign.
He began earning more ice time near the end of the season as he improved his defensive play.
On 13 April 2006, he scored the game-winning overtime goal against the Vancouver Canucks for the Sharks to clinch a playoff berth, despite San Jose having previously been eight points out of a playoff spot with a month-and-a-half remaining in the season.
Ehrhoff added eight points over 11 post-season games—first among team defencemen—in his first Stanley Cup playoffs as the Sharks were eliminated in the second round by the Edmonton Oilers.
He then signed a two-year contract worth US$1.7 million in the off-season.

Ehrhoff responded with a career-high 33 points in 2006–07.
He notched a personal-best three assists in one game late in the season in a 3–2 win against the Los Angeles Kings on 27 March 2007.
San Jose were once again losers in the second round of the playoffs, being eliminated by the Detroit Red Wings in six games.
Ehrhoff had two assists in 11 post-season games.
His regular season production decreased to 22 points in the 2007–08 season.
On 28 December 2007, Ehrhoff was awarded a penalty shot during a game against the St. Louis Blues; he missed against Manny Legace, though the Sharks nonetheless still won, 1–0.
Later in the season, Ehrhoff missed four games due to a lower body injury, suffered on 6 April 2008.
After finishing as the second seed in the West, San Jose were defeated in the second round against the Dallas Stars.
Ehrhoff notched five assists in ten playoff games.

Ehrhoff became a restricted free agent once more in July 2008 and re-signed with the Sharks to a three-year contract worth $9.3 million.
 The following season, 2008–09, he reached the 40-point mark for the first time in his career with 42 points in 77 games.
He had missed three games in March 2009 due to a lower body injury.
Ehrhoff's personal success coincided with a franchise year for the Sharks, who earned their first Presidents' Trophy as regular season champions in team history with 117 points.
In the ensuing playoffs, however, they suffered a first-round defeat to the eighth-seeded Anaheim Ducks.
Ehrhoff was held pointless in six games.
With the expectation from Sharks management that Ehrhoff would join their organization either with the NHL club or in the AHL, he was signed to a contract on 22 June 2003. Ehrhoff made his NHL debut on 9 October 2003, against the Edmonton Oilers. He recorded his first point, an assist, on 15 November against the Toronto Maple Leafs. Later that month, he scored his first NHL goal, a game winner against Michael Leighton in a 3–2 win against the Chicago Blackhawks on 26 November. Ehrhoff was selected to play in the 2004 NHL YoungStars Game, along with teammate Jonathan Cheechoo. Aftering helping the Western Conference YoungStars to a 7–3 win over the East, Ehrhoff also did colour commentary during the All-Star Game for a German telecast.
Ehrhoff was often a healthy scratch with the Sharks during his rookie season and spent time with their AHL affiliate, the Cleveland Barons. In 41 games with the Sharks during the 2003–04 season, Ehrhoff recorded 12 points in 41 games, while in the 27 games he played for the Barons, he notched 14 points. He began asserting himself early in his NHL career as an excellent skater with offensive capabilities. Ehrhoff then played a full season with the Barons in 2004–05 due to the NHL lockout, tallying 35 points in 79 games. He was chosen to represent PlanetUSA in the 2005 AHL All-Star Game in Manchester, New Hampshire.
Returning to the Sharks in 2005–06, Ehrhoff recorded a 23-point campaign. He began earning more ice time near the end of the season as he improved his defensive play. On 13 April 2006, he scored the game-winning overtime goal against the Vancouver Canucks for the Sharks to clinch a playoff berth, despite San Jose having previously been eight points out of a playoff spot with a month-and-a-half remaining in the season. Ehrhoff added eight points over 11 post-season games—first among team defencemen—in his first Stanley Cup playoffs as the Sharks were eliminated in the second round by the Edmonton Oilers. He then signed a two-year contract worth US$1.7 million in the off-season.
Ehrhoff responded with a career-high 33 points in 2006–07. He notched a personal-best three assists in one game late in the season in a 3–2 win against the Los Angeles Kings on 27 March 2007. San Jose were once again losers in the second round of the playoffs, being eliminated by the Detroit Red Wings in six games. Ehrhoff had two assists in 11 post-season games. His regular season production decreased to 22 points in the 2007–08 season. On 28 December 2007, Ehrhoff was awarded a penalty shot during a game against the St. Louis Blues; he missed against Manny Legace, though the Sharks nonetheless still won, 1–0. Later in the season, Ehrhoff missed four games due to a lower body injury, suffered on 6 April 2008. After finishing as the second seed in the West, San Jose were defeated in the second round against the Dallas Stars. Ehrhoff notched five assists in ten playoff games.
Ehrhoff became a restricted free agent once more in July 2008 and re-signed with the Sharks to a three-year contract worth $9.3 million.  The following season, 2008–09, he reached the 40-point mark for the first time in his career with 42 points in 77 games. He had missed three games in March 2009 due to a lower body injury. Ehrhoff's personal success coincided with a franchise year for the Sharks, who earned their first Presidents' Trophy as regular season champions in team history with 117 points. In the ensuing playoffs, however, they suffered a first-round defeat to the eighth-seeded Anaheim Ducks. Ehrhoff was held pointless in six games.
Christian Ehrhoff