We analyzed the clinical and laboratory findings and outcome of 173 patients hospitalized at our institution from 1983 to 1994 with multidrug-resistant tuberculosis (MDR-TB) and evaluated outcome. The 173 patients (mean age 40 +/- 1 yr) were predominantly male (92%), African American or Hispanic (80%), and mostly undomiciled. Over half (52%) were known to be HIV-infected. HIV-positive MDR-TB patients had significantly more pulmonary and constitutional symptoms, more extrapulmonary disease, and fewer cavitary lesions on chest radiographs. Fifty-five percent of the patients in the cohort have died; mortality was significantly greater for HIV-positive than HIV-negative (72% versus 20%, p < 0.01). The median duration of survival of MDR-TB patients was 22 +/- 1 mo. Overall, extrapulmonary involvement was a risk factor for shorter survival, while a cavitary lesion on initial chest film and institution of appropriate treatment were positive predictors of survival. In HIV+ patients, only appropriate therapy was associated with prolonged survival (median of 14.1 mo). Interestingly, there was a trend toward better outcome in the first half of the decade reviewed. We conclude that although mortality from MDR-TB is high in both HIV-positive and HIV-negative patients, institution of appropriate therapy is the factor most strongly associated with a favorable outcome. Development of new diagnostic and therapeutic strategies for MDR-TB are urgently needed.