This study is an attempt to examine the patterns of sexual behaviours and the underlying factors among young people in East Africa aged between 10 and 24 years from four countries of Tanzania, Kenya, Uganda and Rwanda. The study reviewed 60 relevant pieces of literature from electronic databases that have examined the objective understudy from different regions. Out of 60 studies reviewed, 31 had specific information from four selected countries in East Africa. The studies were published in English and peer-reviewed journals covering from 2010 through 2021. The current study followed a five-stage methodological framework and the reviewed studies were grouped according to the specific objectives of the current study. The findings that emerged from the review were classified into five main themes which are age at first sex, forms of sexual practices, number of sexual partners and condom use during pre-marital partnerships. The reviewed studies revealed that initiation of sexual debut among young people in East Africa occurs at younger and slightly different ages. Studies have depicted that young people in the region are involved in a wider range of sexual practices ranging from non-coital to coital. Moreover, the reviewed studies have also documented a high level of knowledge about condom availability with low and inconsistent use among adolescents in the region. Furthermore, the reviewed studies have depicted that many adolescents in these countries are engaging in multiple sexual partnerships. A multitude of factors has been reported to influence the prevalence of observed sexual behaviours among adolescents. The study concludes that young East African adolescents are engaging in risky sexual behaviours. Given their numerical strength and indeed the understanding that they are the future of the nations, it is recommended that countries in the region have to invest fully in their education and health by providing comprehensive sexual health education. This should be accompanied by supplying effective reproductive health services at their disposal. Failure on that, many young people in this region will continue to be predisposed to several sexual and reproductive health problems that would negatively shutter not only their dreams but also cripple the family well being and the nation’s development.