The aim of this study was to evaluate the outcomes of the therapy applied, and affecting factors, in tuberculosis patients. Demographic data, microbiological results, radiological properties, and therapy outcomes of 253 tuberculosis patients, who had been treated and followed between 2001 and 2002 in İstanbul Eyüp Struggle Dispensary, were analyzed, and factors that might have affected the outcomes were detected. Mean age of patients was 32.0 ± 14.4, and 74 of them were female, 179 were male. The success of treatment was 92%, and cure rate was 83%. No relation was found between the treatment success and age group, marital status, history of contact, being old patient or new patient, and hospitalization. A negative relation was found between the success of treatment and male gender, smoking, educational status of primary school and lower, retreatment of defaulter, rifampicin resistance, and presence of cavity in pretreatment radiological appearance (p<0.05). According to the logistic regression multivariate analysis, rifampicin resistance was the only factor that negatively affected the success of the treatment [OR=15.9 (95% CI 2.2-117.4]. As a result, the desired rate of treatment success and cure rate had been achieved in tuberculosis patients in this particular dispensary. Treatment success is negatively affected by rifampicin resistance. We conclude that, more careful analysis and follow up all patients with directly observed treatment may increase the treatment success and cure rate.