ABSTRACT Use of computers a vital role in the current society, particularly in the communication sector, where there is realization of increasing number of internet users. Use of internet may prove useful in online car purchasing for clients across the country and globe at large. This made it easy to communicate between the client and the seller. These has led to Efficient and secure transactions hence eliminating vices such as conning and undelivered orders and also lost tracing of purchased cars from abroad or within the East African Community at large. The experts and the involved stakeholders posts images and prices of the cars and then customers of prospective customers sends requests for the specific cars into the Company’s database via internet, USSD, text, calls, and e-mails among other online platforms. This system is user-friendly and is easy-to-use among all classes of literate customers. This project aimed at developing an Online Car Purchasing system where sellers are able to sell cars easily. Therefore it has been used by not only usual people, but also by car dealers and retailers want to easily sell their cars securely and for accountability. This system has achieved the objectives of this study by designing and developing an online system using HTML, PHP and JavaScript. This has saved a lot of time for system evolution since it won’t call for coming up with new requirements. Besides the incremental model will be used which unlike the waterfall model is efficient for this project since it is of a smaller scale. .