Unsolved Mysteries uses a documentary format profiling real-life mysteries and features reenactments of unsolved crimes, missing persons, conspiracy theories and unexplained paranormal phenomena (alien abductions, ghosts, UFOs, and “secret history” theories).

The concept of Unsolved Mysteries was created upon a series of three specials produced by John Cosgrove and Terry-Dunn Meurer that they pitched to NBC in 1985 and were shown in 1986 called “Missing… Have You Seen This Person?”. The success of the three programs led to Cosgrove and Meurer to broaden the program to include mysteries of all kinds. The pilot of Unsolved Mysteries was a special that aired on NBC on January 20, 1987 with Raymond Burr as host/narrator to a rousing success. Six more specials aired with the next two being hosted by Karl Malden and the final four by Robert Stack for the remaining 1987–1988 season.

In 1988, the show became a weekly run series on NBC. The show would lose some of its popularity after the 1993–1994 season. Until 1998, the show was hosted by Stack, and during its brief 2-year run on CBS, co-hosted by Virginia Madsen in 1999. Later episodes featured journalist Keely Shaye Smith and television host Lu Hanessian as correspondents in the show’s tele-center, from where they provided information on updated stories. Due to failing health, Stack quit hosting the show in 2002 and died a year later. In 2008, Spike revived the series, and it is now hosted by Dennis Farina. The show was known for its eerie theme song composed by Michael Boyd and Gary Remal Malkin, as well as Stack’s unmistakable voice and presence, which became synonymous with the show. The theme song was later changed four times in 1993, 1996, 1997, and 2001 until ending in 2002.