Human Immunodeficiency Virus (HIV) is primarily transmitted through specific bodily fluids such as blood, semen, vaginal fluids, rectal fluids, and breast milk. Among these, sexual transmission is the most common route of infection worldwide. HIV transmission through sexual activities occurs when the virus present in the infected partner’s bodily fluids enters the bloodstream of the uninfected partner, typically through mucous membranes or small tears in the skin. Understanding the various modes of sexual transmission and the factors that increase the risk is essential for prevention and awareness. HIV can be transmitted through different types of sexual activities, including vaginal intercourse, anal intercourse, and, to a lesser extent, oral sex. Vaginal intercourse is one of the most common modes of transmission. During unprotected vaginal sex, the virus can pass from an infected male to a female through semen entering the vaginal canal. Similarly, transmission can occur from an infected female to a male through exposure to vaginal fluids. The inner lining of the vagina and cervix is delicate and can allow the virus to enter the bloodstream, especially if there are microscopic tears or abrasions. Women are biologically more vulnerable to HIV infection during vaginal intercourse due to a larger exposed mucosal surface area. Anal intercourse carries a significantly higher risk of HIV transmission compared to vaginal intercourse. This is because the lining of the rectum is thinner and more fragile than that of the