Socioeconomic problems limit the access of drug users to health-care services. This descriptive cross-sectional study was carried out by making use of the medical records of new case tuberculosis (TB) patients hospitalized at Masih Daneshvari Hospital, the national referral centre in Iran, from 2003 to 2006. Demographic and personal characteristics of the patients and type of disease were collected and categorized. Of the 944 patients with confirmed TB, 143 (15.1%) were drug users, among whom 140 (97.9%) were men with just three women drug users. The mean age of the drug users group was 43.04 +/- 13.81 years. The type of drug used was opium in 100 cases (69.9%), heroin in 29 (20.3%), opium and heroin together in four (2.8%) and all three, opium, heroin and crack, in two (1.4%). For 238 high-risk patients, an HIV test was performed and HIV infection was confirmed in 33 cases. Patient delay was longer in drug users (P = 0.000) against other patients, whereas diagnosis delay was shorter (P = 0.007). Drug susceptibility tests were performed for 515 patients with positive cultures. One hundred and thirty-three (14.1%) were found to have 'any resistance' to anti-TB drugs, and 10 (1.1%) individuals had multidrug-resistant TB. Twenty-six (19.5%) of the individuals who showed resistance to first-line agents were drug users. There was no significant relation between drug resistance and drug use (P = 0.4). In conclusion, it seems that active case finding for TB and HIV in addict cases must be contained in harm reduction packages. Moreover, the manifestations of the disease should be considered seriously regardless of attributing them to drug use.