INTRODUCTION: Recent researches had shown that, in principle, computer-assisted design, computer-assisted manufacture and rapid prototype technologies (CAD/CAM) can be successfully applied to the fabrication of removable partial denture (RPD) alloy frameworks and replace laboratory crafting techniques. The (CAD/CAM) techniques have been widely used for a long time to manufacture dental prostheses. Polyoxymethylene (POM) also known as acetal resin has been used as an alternative tooth- colored denture base and denture clasps material since 1986 and was promoted primarily for superior esthetic. OBJECTIVES: To evaluate clinically the use of Polyoxymethylene partial dentures designed and fabricated by using CAD/CAM technology compared to conventional cobalt chromium partial denture through both the masticatory efficiency and patient satisfaction. MATERIALS AND METHODS: This clinical trial was conducted on twenty mandibular partially edentulous patients (Kennedy class I) who received two types of RPD. Type I was Polyoxymethylene partial denture designed and fabricated by using CAD/CAM Technology and Type II was cobalt chromium partial denture fabricated using the conventional technique .At time of denture insertion, the masticatory efficiency of both types of dentures was evaluated for each patient .After 3 months of denture use, each patient was clinically evaluated through both the masticatory efficiency and patient satisfaction. RESULTS: Type I RPD showed better masticatory efficiency than Type II RPD but without statistical significant values at different follow up periods. Patients showed more satisfaction with type I RPD than with type II RPD with a significant value. CONCLUSIONS: Polyoxymethylene partial denture designed and fabricated by using CAD/CAM Technology is a favorable treatment for partially edentulous patients showing improvement of masticatory efficiency and favorable patient satisfaction.