Approaching the NHL trade deadline in 2008, Fedorov was traded to the Washington Capitals in exchange for prospect Theo Ruth.

The following summer, Fedorov signed a one-year, $4 million contract with Washington.
In 2008–09, what would become his final season in the NHL, Fedorov passed Alexander Mogilny for most goals scored by a Russian-born hockey player, a record previously held by Mogilny, who scored 473 goals.

In a 2009 interview, Scotty Bowman recalled a conversation between Wayne Gretzky and himself: "I talked to Wayne Gretzky about that six or seven years ago and he said to me: 'I couldn't play forward and defence.
Mario couldn't do it.
Jagr couldn't play defence.
But Sergei could.
He was a hell of a player.'"
A few years later, in a 2015 interview, Bowman stated he thought Fedorov "could have been an all-star defenceman, but he developed his offensive skills".

On April 28, 2009, in one of his final games in the NHL, after scoring the game-winning goal in the 2009 playoffs against the New York Rangers in a 2–1 Game 7 contest, then-Capitals head coach Bruce Boudreau stated in a press conference, "Let's face it, sometimes experience pays off.
He knew what he had to do, when to do it, and that's what makes him one of the greatest players, ever."
Teammate Alexander Ovechkin added, "He's our leader ... He's our best guy in the locker room.
He showed it.
He's our best guy.
He has more experience than anybody in this locker room.
He knows how to play like that.
He just shows his leadership."

In his book, Jeremy Roenick spoke about Fedorov being one of his top ten favourite players to play against: "He was a horse, bigger than you'd think he was.
He could skate, handle the puck like a magician, and check you until you hated him.
You didn't get a break when you played centre against Detroit in those days."
He added, "Today we talk about Evgeni Malkin and Alex Ovechkin, but neither of those guys could skate with [Alexander] Mogilny or Fedorov or [Pavel] Bure."
Approaching the NHL trade deadline in 2008, Fedorov was traded to the Washington Capitals in exchange for prospect Theo Ruth.
The following summer, Fedorov signed a one-year, $4 million contract with Washington. In 2008–09, what would become his final season in the NHL, Fedorov passed Alexander Mogilny for most goals scored by a Russian-born hockey player, a record previously held by Mogilny, who scored 473 goals.
In a 2009 interview, Scotty Bowman recalled a conversation between Wayne Gretzky and himself: "I talked to Wayne Gretzky about that six or seven years ago and he said to me: 'I couldn't play forward and defence. Mario couldn't do it. Jagr couldn't play defence. But Sergei could. He was a hell of a player.'" A few years later, in a 2015 interview, Bowman stated he thought Fedorov "could have been an all-star defenceman, but he developed his offensive skills".
On April 28, 2009, in one of his final games in the NHL, after scoring the game-winning goal in the 2009 playoffs against the New York Rangers in a 2–1 Game 7 contest, then-Capitals head coach Bruce Boudreau stated in a press conference, "Let's face it, sometimes experience pays off. He knew what he had to do, when to do it, and that's what makes him one of the greatest players, ever." Teammate Alexander Ovechkin added, "He's our leader ... He's our best guy in the locker room. He showed it. He's our best guy. He has more experience than anybody in this locker room. He knows how to play like that. He just shows his leadership."
In his book, Jeremy Roenick spoke about Fedorov being one of his top ten favourite players to play against: "He was a horse, bigger than you'd think he was. He could skate, handle the puck like a magician, and check you until you hated him. You didn't get a break when you played centre against Detroit in those days." He added, "Today we talk about Evgeni Malkin and Alex Ovechkin, but neither of those guys could skate with [Alexander] Mogilny or Fedorov or [Pavel] Bure."
Sergei Fedorov