Abstract Unsafe sex was very common among the youth as they got involved into unprotected and unsafe sex practices due to factors like lack of parental support and guidance, breakdown of parent-child communication and cultural factors among others. The purpose of the study was to identify the factors affecting effective use of condoms among adolescents of Mayengo Parish, Kamuganguzi Sub County, Kabale District. The study design was descriptive and simple random sampling procedure was used to select 40 respondents. Data was collected by use of a semi structured interview guide. The findings showed that 40 (100%) were currently involved in a sexual relationship, 37 (92.5%) knew about the safe sex practices, 34 (85%) knew how to effectively use condoms, 35 (87%) agreed that not knowing about effective condom use had made them have live sex, 30 (75%) had ever had unsafe sex, 10 (25%) respondents said youth did not use condoms because they wanted to know how sex without a condom felt, 8 (20%) who wanted to show love to their partners, 24 (60%) sometimes used condoms while playing sex, 31 (77.5%) said cross generational sexual relationships were sometimes common in their area, 25 (62.5%) always felt shy to ask for condoms at the shop/hospital, 32 (80%) intended to use protection the next time they had sex, 34 (85%) had never been sensitized about the importance of using condoms. The study concluded that although all the respondents were knowledgeable and had ever heard of safe sex practices and correctly described the effective way of using condoms, all the respondents were sexually involved. The majority of respondents had a very early sexual debut and had ever had unprotected/live sex due to various reasons including curiosity and wanting to know how it felt like when having live sex, peer pressure or wanting be like their friends, non-availability of condoms among many other factors. The majority of respondents had ever had unsafe sex. The key recommendations included adequate nationwide sensitization programs on the dangers of unsafe sex as well as what they could do to ensure safe sex, offering adolescent friendly sexual and reproductive health services are increased such that services are brought within the reach of youth to improve utilization, ensuring that protective gears such as condoms were provided free of charge to youth and adequate sensitization about the importance of practicing safe sex practices.