Sexually transmitted diseases (STDs) including AIDS are becoming a major public health problem in developing countries worldwide. All the adult patients attending VCTC and STD clinics of Assam Medical College between May 2002 and December 2005 were enrolled in the study. Records of patients with high-risk sexual behavior and presence of STD on clinical examination were recorded in a predesigned proforma. Of 479 individuals, 186 (38.8%) had evidence of STD and 70 were positive for HIV. Most (64%) were in the age group of 15 to 30 years. Candidiasis (vulvovaginal candidiasis in women and candidal balanitis/balanoposthitis in men) was the most common finding on clinical examination (21.5%) followed by syphilis (17.2%), genital warts (15%), herpes genitalis (11.3%), non-gonococcal urethritis (10.8%), and gonococcal urethritis (7%). High percentage of unmarried people (>45%) reporting with STD, which points to potential danger of HIV transmission in the region.