A Shock to the System is:

• a novel by British author Simon Brett, first published in 1984.
• a U.S. film (1990) by Jan Egleson, based on Brett's book, starring Michael Caine, Swoosie Kurtz, Elizabeth McGovern, and Peter Riegert.

Shock to the System is a 2006 gay-themed mystery film. It is the second film adaptation of a Richard Lipez novel featuring fictional detective Donald Strachey, starring Chad Allen as Strachey and Robert Kaiser as Tobias. The film premiered at the 2006 Outfest film festival before going into rotation on the here! television network.

Graham Marshall already celebrates his anxiously awaited promotion in an advertising company, when he learns that Roger Benham, one of his subordinates, will be promoted instead of him. Frustrated that his hated life will never change, he starts a cunning ploy to take bloody revenge on everyone who humiliated him - starting with his unnerving wife. Written by Tom Zoerner