The series was created by Richard Barton Lewis and produced by PMP Legacy Productions, Showtime Network Inc., and Trilogy Entertainment Group.

Poltergeist: The Legacy debuted on Showtime in 1996, and after Showtime cancelled the show following its third season, the rights were purchased by Sci-Fi Channel, which produced a fourth and final season in 1999.

The series was filmed in Vancouver and Victoria, British Columbia, over four seasons of 22 episodes each.

Special effects for the show were created by several Canadian companies, including C.O.R.E. Digital Pictures, Gajdecki Visual Effects, Lindala Make-Up Effects Inc., and Rainmaker Digital Pictures, along with American companies Pixel Envy and Velocity Visuals.

After the series concluded in November 1999, a spin-off titled Poltergeist: The Beginning was informally discussed at Sci-Fi Channel starting in 2000-2001, but the plans were abandoned by 2002 and never materialized.

Actress Jordan Bayne, who played Julia Walker in the pilot episode, had her character's death continue to affect the other characters throughout the rest of the series.

Daniel J. Travanti's character William Sloan, head of the Ruling House in London, was introduced in season two and departed the show in the episode 'Trapped' after giving himself over to a demon.