Background: Tuberculosis become important challenge to health care settings. Brazil has high prevalence of the disease and Rio de Janeiro has high incidence rates with 30% of cases notified at hospitals.Objective: To evaluate prevalence of initial and acquired drug resistance at a general hospital, reference for aids treatment in Rio de Janeiro and to identify associated factors.Methods: Mycobacterium tuberculosis strains from 165 patients were analyzed, between August 1996 and February 1998.Results: Twenty per cent (33/165) were resistant to at least one drug; 13% (12/165) to isoniazid; 3.64% (6/165) to rifampin and 3.64% (6/165) to both. Among HIV seropositive subjects (52/165); 28.85% (15/52) were resistant to at least one drug. Acquired resistance occurred in 15.79% of 19 patients that mentioned previous antiTB treatment. Association statistically significant was found with non cavitation on X-ray in bivariate analyses (P=0.05). Eighty four patients refereed no previous treatment (NPT). Resistance to 1 or more drugs was found in 28.57% (24/84) of NPT patients. Association statistically significant with initial resistance was found with health care workers (P=0.004), unemployment (P=0.03), and diarrhea (P=0.01) in bivariate analyses. On multivariate analyses, health care workers (P=0.002) remained significantly associated with initial resistance.Conclusions: High resistance rates was found. It corroborates that hospitals needs attention for TB control especially which concerns to health care works infection.