BACKGROUND The emergence of drug resistant mycobacterium has become a significant public health problem creating an obstacle to effective tuberculosis (TB) control. Freedom from TB is possible with timely, regular, complete treatment, with assurance, prevention and management of side effects of antitubercular drugs. Present study was conducted to evaluate common and rare adverse drug reactions (ADR) of CAT IV and CAT V to analyse demographic, radiological and bacteriological profile and treatment outcome in MDR & XDR patients. We wanted to evaluate the common and rare adverse drug reactions of intensive phase treatment of Multi Drug Resistant Tuberculosis (MDR) and Extensively Drug Resistant Tuberculosis (XDR) as per WHO-UMC Causality Assessment Scale. METHODS 76 patients of MDR and XDR Tuberculosis were admitted in DR-TB (Drug Resistant TB) centre, Burdwan Medical College and Hospital and the adverse drug reaction profile of 2 nd line drugs were analysed during the intensive phase from April 2016 to September 2017 after fulfilling the inclusion and exclusion criteria. Treatment was given as per the guidelines of Revised National TB Control Program PMDT (Programmatic Management of Drug-Resistant TB). RESULTS Adverse drug reactions on GI system were nausea 73 patients (96.10%), vomiting 70 (92.10%), acidity 41 (53.9%), and sulphurous belching and hepatitis 1 (1.31%) each. Peripheral neuropathy, hearing deficit, myopathy, skin rashes, hepatitis, nephrotoxicity, cardiac toxicity and convulsion were also observed. In psychosis, 3 (3.95%) had depression and made suicidal attempt. 1 each (1.31%) in hallucination and paranoia. 5 patients (6.58%) had blurring of vision, 2 patients (3.95%) had redness of eyes and one (1.31%) had eye irritation. Reactions were common in first 60 days of the regimen and in patients with BMI ≤18. CONCLUSIONS Vigilant monitoring is required for these patients during the initial period and sputum smear and culture conversion is very well correlated with clinical and radiological improvement.