Originally called Keystone Racetrack, it opened in November 1974 in Bensalem, Pennsylvania, replacing the Liberty Bell Park Racetrack in Northeast Philadelphia as the area's Thoroughbred track.
 When the track was purchased in 1984 by ITB, the racetrack received a new name, Philadelphia Park, a new turf course, and an innovative new way to wager called Phonebet.

In December 1990, the racetrack again changed hands when Greenwood Racing, Inc. (a corporation founded in 1989 by British bookmaking veterans Bob Green and Bill Hogwood) purchased the oval from ITB.
 Full card simulcasting was added, as well as six off-track locations called Turf Clubs, allowing race fans to watch and wager seven days a week.

Late in 1998, Greenwood joined with fellow Pennsylvania corporation, Penn National Gaming, Inc., in expanding into New Jersey with the purchase of Freehold Raceway in Freehold Borough and the operating lease of Garden State Park in Cherry Hill.
 The new partnership, called Pennwood, was expected to pursue off-track and account wagering in New Jersey.
 Garden State Park closed in 2002, and was razed shortly thereafter.
 Simulcasting on cable broadcasting systems (notably those owned by Comcast) was discontinued in March 2010, and shortly replaced by Comcast with TVG Network, who later joined with Harrah's Chester to bring their own simulcasting betting accounts in October 2010.

On August 30, the track was rechristened as Parx Racing and Casino.

Over the years, such notable horses as Shuvee, My Juliet, Spectacular Bid, Revidere, Summer Squall, and Broad Brush found their way to the winner's circle at Parx Racing and Casino.
 The track became famous as the original home of 2004 Kentucky Derby and Preakness Stakes champion Smarty Jones, who placed second in the Belmont Stakes, narrowly missing the Triple Crown.

In November 2014, it was revealed that Parx was requiring jockeys to sign a waiver as a condition of riding there.
It is believed that the waiver stemmed from a court judgement against Parx in favor of the family of Mario Calderon, an exercise rider who suffered fatal injuries in an incident on the Parx backstretch in 2010.
The judgement required Parx to pay Calderon's family $7.8 million in damages.
The Jockeys' Guild said that the waiver contained language "inconsistent with the laws of Pennsylvania" and it would instruct its members against signing it.

In 2017, Parx hosted the fourth annual Jockeys and Jeans fundraiser for the Permanently Disabled Jockeys Fund.
 The fundraiser has raised more than $650,000 with the goal of raising $200,000 in 2017.
 The event was previously held in Tampa Bay Downs, Indiana Grand and Gulfstream Park.

On March 19, 2018, a major accident occurred during the 9th race, in which hall of fame jockey Jose Flores was sent to a hospital following the incident.
It was announced that he would be placed on life support a day later.
The horse however had to undergo animal euthanasia.
Flores was pronounced dead on March 22, 2018 at 12:42 pm.
Originally called Keystone Racetrack, it opened in November 1974 in Bensalem, Pennsylvania, replacing the Liberty Bell Park Racetrack in Northeast Philadelphia as the area's Thoroughbred track.  When the track was purchased in 1984 by ITB, the racetrack received a new name, Philadelphia Park, a new turf course, and an innovative new way to wager called Phonebet.
In December 1990, the racetrack again changed hands when Greenwood Racing, Inc. (a corporation founded in 1989 by British bookmaking veterans Bob Green and Bill Hogwood) purchased the oval from ITB.  Full card simulcasting was added, as well as six off-track locations called Turf Clubs, allowing race fans to watch and wager seven days a week.
Late in 1998, Greenwood joined with fellow Pennsylvania corporation, Penn National Gaming, Inc., in expanding into New Jersey with the purchase of Freehold Raceway in Freehold Borough and the operating lease of Garden State Park in Cherry Hill.  The new partnership, called Pennwood, was expected to pursue off-track and account wagering in New Jersey.  Garden State Park closed in 2002, and was razed shortly thereafter.  Simulcasting on cable broadcasting systems (notably those owned by Comcast) was discontinued in March 2010, and shortly replaced by Comcast with TVG Network, who later joined with Harrah's Chester to bring their own simulcasting betting accounts in October 2010.
On August 30, the track was rechristened as Parx Racing and Casino.
Over the years, such notable horses as Shuvee, My Juliet, Spectacular Bid, Revidere, Summer Squall, and Broad Brush found their way to the winner's circle at Parx Racing and Casino.  The track became famous as the original home of 2004 Kentucky Derby and Preakness Stakes champion Smarty Jones, who placed second in the Belmont Stakes, narrowly missing the Triple Crown.
In November 2014, it was revealed that Parx was requiring jockeys to sign a waiver as a condition of riding there. It is believed that the waiver stemmed from a court judgement against Parx in favor of the family of Mario Calderon, an exercise rider who suffered fatal injuries in an incident on the Parx backstretch in 2010. The judgement required Parx to pay Calderon's family $7.8 million in damages. The Jockeys' Guild said that the waiver contained language "inconsistent with the laws of Pennsylvania" and it would instruct its members against signing it.
In 2017, Parx hosted the fourth annual Jockeys and Jeans fundraiser for the Permanently Disabled Jockeys Fund.  The fundraiser has raised more than $650,000 with the goal of raising $200,000 in 2017.  The event was previously held in Tampa Bay Downs, Indiana Grand and Gulfstream Park.
On March 19, 2018, a major accident occurred during the 9th race, in which hall of fame jockey Jose Flores was sent to a hospital following the incident. It was announced that he would be placed on life support a day later. The horse however had to undergo animal euthanasia. Flores was pronounced dead on March 22, 2018 at 12:42 pm.
Parx Casino and Racing