Between 1969 and 1971, the nonmedical use of propoxyphene hydrochloride (Darvon) by US Army soldiers stationed in West Germany reached epidemic proportions. The major complications observed were respiratory arrest, psychotic reactions, and physical addiction. In 13 soldiers who died due to overdoses, pulmonary edema was the primary anatomical finding at postmortem examination. Physical addiction by the intravenous route in seven soldiers was limited to a maximum of 12 weeks, because propoxyphene injections have an extremely destructive effect on veins and soft tissues. Thrombophlebitis, abscesses, cellulitis, and severe sclerosis of veins developed so rapidly at the sites of injection that addiction was interrupted. Hemolytic anemia occurred in one propoxyphene addict. Control of the epidemic among soldiers required that US Army medical facilities restrict the prescribing of propoxyphene.