Background information: Human immunodeficiency virus/acquired immune deficiency syndrome (HIV/AIDS) is a major public health problem in India. In general, it affects mainly young people who are at their most productive part of life. Despite initial fears that AIDS will be disastrous for the economy, recent experience and estimations have shown that there is a need for reappraisal of its economic impact on society. Research question: From the viewpoint of the society of India, what is the total cost and equivalent annual cost of HIV infections for the period 1986–1995 (10 years) in India? Methods: Type of analysis: Cost-descriptive based on predictive modelling cohort analysis using human capital approach. A discount rate of 5% was used. The cost of HIV infections include (i) loss of productivity among HIV patients due to sickness and death, (ii) productivity loss due to caregivers of AIDS patients, and (iii) cost of management of AIDS patients. To estimate the loss of productivity due to premature death attributable to AIDS, a life table approach using two cohorts, one with and one without HIV/AIDS infection at assumed rates was used. The demographic data of 1991 census were used. The difference in the person-years lived in the two scenarios gave the person-years lost due to HIV/AIDS. This was calculated separately for rural and urban areas. To convert this to monetary terms, national per capita income for 1992–93 of Rs. 5529 was used. The data on the days of inpatient care and the cost of management of AIDS patients were based on currently available data and ‘expert opinion’. We analysed, using three different sets of assumptions for determination, the low, medium and high estimates of the impact of HIV/AIDS in India. Some of the costs were not included in the present analysis: (i) use of antiviral AZT, (ii) cost of retraining of new workforce, (iii) cost of strengthening of health care system, (iv) cost of research and development, (v) cost of communication activities, (vi) cost of prevention of vertical transmission, and (vii) the intangible cost of pain and suffering to the patients and their families. Results: The total cumulative number of HIV-infected persons in India until 1995 was estimated to be 1.5 million (low estimate), 2.5 million (medium estimate) and 4.5 million (high estimate). The estimated total annual cost (in billion Rupees) of HIV/AIDS in India under low, medium and high assumptions was 6.73, 20.16 and 59.19, respectively. Cost of treatment of AIDS and loss in productivity were the two major components of the cost. Conclusions: The estimated annual cost of HIV/AIDS appears to be about 1% of the GDP of India if based on high assumptions. However, as mentioned earlier, all costs of HIV have not been taken into account. Its significance has to be assessed in the context of annual growth of GDP (3.5%) and cost of other major diseases in India.