The study was conducted in order to examine the sexual HIV transmission risky behaviour of people living with HIV and AIDS (PLWHA) in Kinondoni Municipality, Dar es Salaam. It also examined factors affecting HIV and AIDS, and assessed people’s perceptions and attitudes towards HIV and AIDS. The primary data were collected from 100 respondents through questionnaire survey, interviews and participant observations. The secondary data were collected from reviewing various literatures from Kinondoni Municipality and other sources. The study relied on quantitative data analysis, based on the compiled data provided by the Statistical Package for Social Sciences (SPSS) tool .The findings from this study showed that more females were prone to HIV and AIDS compared to males. The sexual HIV transmission risky behaviour for females was found to be associated with factors including poverty, unemployment, and inadequate education. The study further revealed that respondents of different ages were affected differently by HIV and AIDS. The factors leading to sexual HIV transmission risky behaviour include having multiple sexual partners, unprotected sexual behaviour, and engagement in commercial sex. The study concludes that few people were knowledgeable, the majority were uncertain, and very few disagreed about HIV and AIDS. The study recommends enhancement of education to increase awareness on HIV and AIDS, introduction of income generating activities, introduction of law enforcement to minimize new infections, and promote safe sex to avoid further infections.