Patients with drug-susceptible tuberculosis (TB) show good tolerance of the medications used and have few side effects. However, medications used to treat multidrug-resistant tuberculosis (MDR-TB) have many known side effects. Here, we studied the occurrence of side effects due to treatment of patients with MDR-TB.We conducted a retrospective and consecutive review of the medical records of 256 patients who received treatment for MDR-TB between January 2006 and December 2011.One or more side effects were observed in 95 (37.1%) of the 256 patients. These side effects led to the suspension of the use of 1 or more drugs from the regimen of individualized treatment prescribed for 44 of the patients (17.2%). The side effects observed most frequently included gastrointestinal disturbance (18.4%), psychiatric disorder (5.5%), arthralgia (4.7%), hepatitis (3.9%), peripheral neuropathy (3.1%), hypothyroidism (2.3%), epileptic seizures (2%), dermatological effects (2%), ototoxicity (1.6%), and nephrotoxicity (1.2%). The treatment was successful in 220 (85.9%) patients with MDR-TB.Our study may help in formulating strategies for the timely and aggressive management of drug side effects. This may reduce the suspension of therapy and increase the rate of clinical success.