We describe 3 unusual autoerotic fatalities in which propane gas was used to induce hypoxia. To our knowledge, these are the first cases of their kind to be reported and described in depth, although brief references to similar cases have appeared. The case histories of 3 white males, aged 22, 42, and 62 years, are described with emphasis on the scene and circumstances and the identification of propane from autopsy materials. In one case, unusual paraphilia and multiple foreign bodies in the rectum were noted. These 3 cases illustrate an unusual form of autoerotic practice in which hypoxia is induced by propane inhalation, unlike the usual neck compression that has been previously described in depth. The importance of scene reconstruction and an awareness of this phenomenon is stressed.