Throughout the world, road traffic injuries (RTIs) are a vastly silent encroaching public health problem. Motorcyclists and pillion passengers are two of the most vulnerable road users worldwide. In Kenya, the annual incidence reports on RTIs amongst these groups had been on the rise in recent years. In 2017, 1,270 injuries were recorded while 2018 had 1,587 RTIs amongst these two groups. In 2019, 2,911 injuries were reported and 4,575 injuries in 2020. The purpose of the study was to assess the association between the utilization of Personal Protective Equipment (PPE) and the prevalence of Road Traffic Injuries (minor and major) amongst motorcycle riders in Kibera constituency, Nairobi County, Kenya. Specific objectives were to determine the prevalence of RTIs amongst motorcycle riders, to determine the level of PPE utilization amongst the motorcycle riders, to evaluate the association between the utilization of PPE and the severity of injury sustained by the riders, and to evaluate the effect size of the association between the utilization of PPE and the type of injury sustained by motorcycle riders. A cross-sectional analytical study design was used to gather both qualitative and quantitative data from the motorcycle riders in Kibera constituency. Questionnaires were used to gather information on injuries sustained from the local hospitals and clinics visited by the motorcycle riders in Kibera constituency. A checklist was used to gather data on the utilization of personal protective equipment by motorcycle users in Kibera constituency. The total number of registered motorcycles (2956) was subjected to Slovin’s formula (n)=N/(1+Ne^2) to obtain a representative sample of 353 motorcycle riders who participated in the study. Data was analyzed using SPSS V22 and MS-excel software. Data was subjected to bivariate analysis with crosstabs for case classification, Chi square to evaluate the association, and Cramer’s V to measure the effect size of the association. A 95 percent confidence level was used for the whole analysis of this study. The 0.05 level of significance was used throughout the study to test the significance of the association between PPE utilisation and severity of injury when an accident occurred. Utilisation of PPE was negatively associated with severity of injury. Further, while Helmet, Jacket, Heavy trousers and Gloves reduced severity of injury, Reflective vest and Boots were not significantly associated with severity of injury sustained by the Motorcycle riders.