This report investigates the linkages between family structure, family and peer communication about sexuality and accurate knowledge of transmission and prevention strategies. Data from the Cameroon Family Life and Health Survey, conducted in 2002 were used. Respondents were aged 10 years and over and sampled 765 households from the 75 localities forming the administrative prefecture of Bandjoun. Details questionnaires were used to gather data for the survey and it had a 97% response rate. Some 42% of respondents had accurate knowledge of HIV transmission rates, but 21% had inaccurate data (mosquito bites can transmit HIV). Only 9% of respondents knew all the HIV preventive strategies. Multivariate analysis revealed that family structure, communication with parents/guardians and peers about sexual topics were significantly associated with accurate HIV knowledge. Age, education, sexual experience and migration were also associated with accurate HIV knowledge. Living in poor households or neighborhoods was significantly associated with increased inaccurate knowledge of HIV transmission modes and prevention strategies. The family environment is a critical source of information on HIV. This must be taken into account when designing HIV prevention programs in the future.