Public transport is adopted to provide mobility to people who do not have access to private cars or offer an alternative option to individual mobility. Nowadays, cities are adopting Public transportation for many Purposes, such as providing mass mobility, managing traffic congestion, controlling air pollution, reducing energy consumption, and creating developmental opportunities. To collect transport fare efficiently, cashless payments on Public bus transportation are additionally adopted and progressively prevalent and offer new opportunities for a Public transport company to collect those fares. The aim of this research was to evaluate passenger's acceptance of cashless payment system that is made available for them. In this research, technology acceptance and Technology readiness index models have been merged because these models are relevant to assess how a certain technology is embraced and accepted by users to evaluate passengers' acceptance of a cashless payment system adopted by a certain transportation company. This research used the case of Kigali city (Rwanda) which has fully introduced a Public bus transportation system and that bus is fully using cashless payment, and from that, we have found out that two variables are not significant(Attitude and Insecurity) and the remaining ones (Awareness, Discomfort, Intention To Use Cashless Payment System, Innovativeness, Optimism, Perceived ease of use and usefulness) are significant.