HIV/AIDS knowledge in Kenya is universal in that 99% of both male and female have heard of the epidemic and how it can be avoided. Despite the widespread knowledge of HIV/AIDS, comprehensive HIV knowledge which refers to one being able to correctly identify the modes of HIV transmission and reject the most common misconception about HIV transmission among the youths, is just above average, 65% for males and 54% for females. There seems to be lack of information on the effects of the determinants of comprehensive HIV knowledge among the youths. This study, using KDHS 2014 data, investigates the effect of the relationship between condoms use and comprehensive HIV knowledge among the youths in Kenya. A logistic regression model is used to explore the effects of relationship between condoms usage and comprehensive HIV knowledge among the youths. Comprehensive HIV knowledge among the youths aged 15-19 was 12.9% while those aged 20-24 was 87.1% and on average 55.5%. Significant association was found between consistent use of condoms during the first sexual intercourse and comprehensive HIV knowledge with a p-value < 0.001. 78.8% of the youths consistently use condoms during their first sexual intercourse. Interestingly, results showed that condoms use have no effect on comprehensive HIV knowledge which means there are other factors that influence comprehensive HIV knowledge that seems to suppress the effect of condoms use. Nevertheless, much intervention among the youths aged 15-19 should be considered to increase the level of comprehensive HIV knowledge. Further research need to be conducted to determine the effect of the relationships between other correlates of comprehensive HIV knowledge among the youths in Kenya.