Sudden death due to the inhalation of halogenated hydrocarbons is a well-documented phenomenon in the scientific and medical literature. Recently, there has been sporadic information suggesting that nonhalogenated hydrocarbons may cause potentially fatal cardiac arrhythmias. This report documents five sudden deaths due to inhalation of nonhalogenated hydrocarbons: n-butane, isobutane and propane. The hydrocarbons were identified by headspace gas chromatography in blood, brain, and lung tissue. Case histories, toxicological findings and analytical procedures are discussed.