A decline in Human Immunodeficiency Virus (HIV) prevalence rates have been observed among females ages 15 to 19 years and 20 to 24 years in Zimbabwe between 2005 and 2010. However, for males 15 to 19 years, rising trends were observed, whereas for males ages 20 to 24 years, rates fluctuated between 2005 and 2011. The purpose of this cross-sectional study was to examine relationships between sexual behaviors and practices and HIV prevalence among young males and females ages 15 to 24 years in Zimbabwe. Guided by constructs of proximate determinants framework, extracted data from two National Demographic Health surveys of 2005/06 and 2010/11 were analyzed using chi square and binary logistic regression. This study revealed that sexual practices, relationship status, and education status increase the odds of being HIV positive differently among 15 to 19-year-olds and 20 to 24-year-olds based on gender and changes through time. Significant relationship existed between HIV positive serostatus and total number of life time partners among females 15 to 19 years and 20 to 24 years; lack of condom use among males 20 to 24 years in 2005/06; early sexual debut and lower education status among females 20 to 24 years; and being widowed, separated, or divorced among males and females 20 to 24 years in 2010/11. The Odds of being HIV positive for males ages 15 to 19 years was not predicted by sexual practice, creating a need for future study. This study can contribute to positive social change by providing information about the associations between HIV serostatus and the assessed risk factors, which may help promote awareness about HIV infection risk, thereby helping develop and implement targeted public health interventions to reduce the burden of HIV.