Adverse Drug Reactions (ADRs) constitute an enormous burden for the society. The aim of the present study was to detect, document, assess and report the suspected ADRs. A prospective-observational study was conducted in the Department of Pulmonary Medicine of a tertiary care hospital for 12 months from April 2014 to March 2015. Patients on RNTCP (Revised National Tuberculosis Control Programme, India) MDR-TB (Multidrug resistant tuberculosis) regimen were enrolled. Detected and suspected ADRs were analysed for causality, severity and preventability using appropriate validated scales and were reported. A total of 121 ADRs were detected, documented, assessed and reported during the study period. Assessment of severity of the suspected ADRs revealed that 23.14% of suspected ADRs were severe and 28.29% of ADRs were moderate in severity. Causality assessment was done which revealed 61.1% of ADRs were certainly drug-related. The majority of patients who had suffered from ADRs were above 20 years. Ototoxicity was most common (37%) and the drug mostly associated with ADRs was kanamycin (27%). Preventability of ADRs was assessed; and the results revealed that 15.7 % of ADRs were definitely preventable. Measures to improve detection and reporting of adverse drug reactions by all health care professionals is recommended to be undertaken, to ensure, and improve patient's safety and adherence to MDR-TB regimen.