The data on alcoholism presented in this paper were extracted from a major follow-up study of active and discharged methadone patients conducted from 1974 through 1977 in New York City. Alcoholism is a factor in 26% of the terminations from methadone treatment. It is also the leading cause of death in treatment and the second leading cause of death, following complications with opiates, in the post-treatment period. Also, patients with episodes of excessive drinking have markedly lower survival rates over a 10-year period when compared to patients who are social or moderate drinkers.