Introduction: This study evaluated the effi cacy of retreatment of pulmonary tuberculosis (TB) with regard to treatment outcomes and antimicrobial susceptibility testing (ST) profi les. Methods: This retrospective cohort study analyzed 144 patients treated at a referral hospital in Brazil. All of them had undergone prior treatment, were smear-positive for TB and received a standardized retreatment regimen. Fisher's 2-tailed exact test and the χ 2 test were used; RRs and 95% CIs were calculated using univariate and multivariate binary logistic regression. Results: The patients were cured in 84 (58.3%) cases. Failure was associated with relapsed treatment and abandonment (n=34). Culture tests were obtained for 103 (71.5%) cases; 70 (48.6%) had positive results. ST results were available for 67 (46.5%) cases; the prevalence of acquired resistance was 53.7%. There were no signifi cant differences between those who achieved or not therapeutic success (p=0.988), despite being sensitive or resistant to 1 or more drugs. Rifampicin resistance was independently associated with therapeutic failure (OR: 4.4, 95% CI:1.12-17.37, p=0.034). For those cases in which cultures were unavailable, a 2 nd model without this information was built. In this, return after abandonment was signifi cantly associated with retreatment failure (OR: 3.59, 95% CI:1.17-11.06, p=0.026). Conclusions: In this cohort, the general resistance profi le appeared to have no infl uence on treatment outcome, except in cases of rifampicin resistance. The form of reentry was another independent predictor of failure. The use of bacterial culture identifi cation and ST in TB management must be re-evaluated. The recommendations for different susceptibility profi les must also be improved.