BACKGROUND Drug information can be obtained from various sources such as National Formularies, drug package inserts (PI), other sources such as Monthly Index of Medical Specialities (MIMS), Current Index of Medical Specialities, and the information available with the regulators. Any variation in the information available in different sources can promote irrational drug use. In this study, we assessed this variation in a sample of commonly used drugs. MATERIALS AND METHODS Fifty commonly used drugs were analyzed for any variation (both quantitative and qualitative) in information on indications as mentioned in commonly used drug information sources such as Central Drugs and Standards Control Organization (CDSCO) website, National Formulary of India (NFI), MIMS, and PI of medicines. RESULTS We observed a variation in average number of indications per drugs given in CDSCO (2.2 ± 0.25), NFI (3.51 ± 0.42), MIMS (2.98 ± 0.29), and PI (3.18 ± 3.52). The CDSCO and NFI did not contain information about indication for 10 and 17 drugs, respectively, while MIMS and PI contained information about all the selected drugs. A subset analysis was done for 24 such drugs which were mentioned in all the four sources and it was found that NFI had listed the maximum number of indications per drug (3.79 ± 0.53), followed by PI (3.08 ± 0.44), MIMS (3.04 ± 0.51), and CDSCO website (2.66 ± 0.37) and this difference was found to be statistically significant (P = 0.02). We also observed some gross qualitative variation regarding drug information given in different sources. CONCLUSION Variation exists in the quantity and quality of information available on indications about drugs available in various sources. Necessary steps need to be taken to harmonize drug information available across various sources so as to provide reliable and uniform drug information thereby promoting rational drug use.