The resurgence of tuberculosis in New York City has been largely attributed to the acquired immune deficiency syndrome (AIDS) epidemic. However, historical events predating the advent of AIDS and worsening economic and social conditions, including a rise in homelessness, have contributed significantly to the increase. We prospectively studied 224 consecutive patients with tuberculosis admitted to a large public hospital in New York over the first 9 months of 1988. Initial assessment included medical status, human immunodeficiency virus (HIV) risk factors, and detailed social information, including substance abuse history and housing status. All patients were tracked after discharge to determine compliance and cure rates. Tuberculosis patients were predominantly male (79%), with high rates of alcohol use (53%), intravenous drug and/or "crack" cocaine use (64%), and homelessness or unstable housing (68%). Half the patients had AIDS or AIDS-related complex (ARC) or were HIV antibody positive. A total of 178 patients were discharged on tuberculosis treatment, but 89% of these were lost to follow-up and failed to complete therapy. Of the 178 discharged patients, 48(27%) were readmitted within 12 months with confirmed active tuberculosis. Of these patients, 40 were discharged on treatment and at least 35 were again lost to follow-up. In a multivariate regression model noncompliance was significantly associated with the absence of AIDS or ARC (p less than 0.001), homelessness (p less than 0.005), and alcoholism (p less than 0.05). Because HIV infection and tuberculosis converge in a subpopulation with high rates of substance abuse and homelessness, the problem of ensuring treatment compliance may grow considerably in the future.(ABSTRACT TRUNCATED AT 250 WORDS)