Study on a cohort of injecting drug users (n = 76) was initiated in June, 1994 with the objective of documenting the clinical presentation of HIV and its progression with time. The participation in the study was voluntary. An informed consent was taken from the subjects before they were enrolled in the study. The subjects were followed up every 45 days for clinical and laboratory examination and analysis made after 27 months of the study. The study had a follow-up rate of 65 per cent. The commonest feature observed in stage I (n = 47) was persistent generalized lymphadenopathy (83%), in stage II (n = 40) was body weight loss < 10 per cent (37.5%), in stage III (n = 32) was pulmonary tuberculosis (56.3%) and in stage IV (n = 9) was cryptosporidial diarrhoea > 1 month (3 cases). Kaposi's sarcoma was detected in one subject. The median time taken for conversion from the date of seroconversion to stage III of HIV infection was observed to be 3.15 yr (95% CI = 2.98-3.58 yr). The rate of HIV progression seems to be significantly faster than that observed in industrialized countries. Age is a cofactor in the rate of progression of HIV. Tuberculosis is the commonest opportunistic infection.