Injecting pharmaceutical opioids for non-medical purposes is a major concern globally. Though pharmaceutical opioids injection is reported in India, the exact proportion of people who inject drugs (PWID) using pharmaceutical opioids is unknown. The objectives of this study were to describe the various types of drugs that are injected by people in India and to analyse the differences between the commonly injected drugs. A cross-sectional, multicentric study covering 22 harm-reduction sites from different regions of the country was conducted. First 50 subjects, chosen randomly from a list of PWIDs accessing services from each site and fulfilling study criteria, were interviewed using a structured questionnaire. Data from 902 male subjects are presented here. Pharmaceutical opioid injectors (POI) accounted for 65% of PWIDs (buprenorphine: 30.8%, pentazocine: 21.8% and dextropropoxyphene: 11.9%). Heroin, injected by 34.3%, was prevalent in most states surveyed. Buprenorphine and pentazocine were not injected in the north-east region, whereas dextropropoxyphene was injected in the north-east alone. Univariate and multivariate logistic regression showed that, compared with heroin injectors, the POI group was more likely to consume alcohol and pharmaceutical opioids orally, inject frequently, share needle/syringes and develop injection-site complications. Among individual POIs, buprenorphine injectors had significantly higher proportion of subjects injecting frequently, sharing needle/syringes and developing local complications. Irrespective of the opioid type, majority of subjects were opioid dependent. Pharmaceutical opioids are the most common drugs injected in India currently and have greater injection-related risks and complications. Significant differences exist between different pharmaceutical opioids, which would be important considerations for interventions.