PIP: The World Health Organization (WHO) criteria for HIV clinical disease were tested among individuals with high-risk behavior in northern India. A questionnaire, based upon history and physical examination alone, standardized by the WHO to include both major and minor signs necessary for the clinical diagnosis of AIDS in adults was applied to 165 consecutive patients attending the STD clinic of Dr. R.M.L. Hospital, New Delhi. All patients were screened for the presence of STDs by the dermatologist in charge of the clinic, with patients fulfilling two major and at least two minor WHO criteria eventually classified as having clinical AIDS based upon the WHO case definition. Each of those patients was subjected to serological confirmation of the clinical suspicion using ELISA and Western blot commercial tests. Of the 165 patients screened, a definite diagnosis of STD was possible in 85. These patients were 20-45 years old (mean age, 30.59 years). All were male and chancroid was the most common STD in the cohort. Of the 85, only one satisfied the WHO clinical criteria for AIDS. Serological investigations, ELISA, and Western blot confirmed the subject's HIV-seropositive status. These results indicate that in northern India, clinical HIV disease remains rare even among individuals with high-risk behavior. The low prevalence of clinical HIV disease in that part of the country makes it difficult to assess the specificity and sensitivity of the WHO clinical criteria for AIDS.