The researchers reported that; millions of tone of RAPA and plastic bottles wastes is generated round the world. Ethiopia is facing rapid urbanization and industrialization leading to packing of different industrial products with plastic bottles which finally becomes waste and on the other side pavements is behaving different structural failure and surface defects before the end of construction period and service year. In order to minimize the above serious problems, this research was initiated to do experimental investigation of recycled asphalt pavement aggregate (RAPA) and waste plastic bottle (PET) as fully and partial replacement of virgin aggregate and bitumen in bituminous hot mix concrete respectively through Marshal mix design method to enhance the desired performance of bitumen concrete mix and to reduce RAPA and plastic bottles disposal problem. Before applying PET bottles as bitumen modifier, optimum bitumen content was determined for recycled asphalt pavement aggregate with bitumen in hot mix concrete which was selected as 4.8%; up on which the effect of PET bottles was experimented. Waste plastic bottles are collected and cut in to pieces using scissors. Then it was melted in oven at 180⁰c for 30 minute. Then weighing the required amount of melt ed plastic(PET) and replacing the bitumen by 0%, 5%, 10%, 15% ,20%&25% by weight of bitumen also recycled aggregate to conventional aggregate by 100/0%, 90/10%, 80/20%, 70/30%, and 60 /40 % by weight. But the first trial test result at 100% recycled asphalt pavement aggregates were fulfilled specification requirement and virgin aggregate is ignored for the preparation of asphalt pavement mix design. The marshal test was held and volumetric properties on each specimen were computed. Based on the laboratory result as per AASHTO T-245 evaluation the optimum plastic content was selected at the specimens that have stability(14.56KN),flow(3.12mm),highbulkdensity(2.53gm/cm3),minimumairvoid(4.98%),VMA(17.19%), VFB(71.01%),values. The optimum RAPA and plastic content (PET) are selected at 100% and 10% by weight respectively. Lastly the modified hot mix asphalt is compared to conventional hot asphalt mix design which was done by the company for Fiche to Guaha Tsion reconstruction and over layer asphalt road project and the stability of PET and RAPA modified asphalt mix is increased by 11%, flow value also decrease by 6% and the value of VMA, VMT and VFB of waste PET and RAPA modified asphalt mix slightly increases when it is compared to conventional asphalt as per AASHTO T-245. This study concluded that, partial replacement of bitumen (80/100) and 100% replacement of virgin aggregate by RAPA and plastic (PET) can increase the overall performance of bitumen concrete mix. Finally this study recommends it is better to apply this new construction technology on the ground and to adopt it. It is better to know the cost benefit analysis on replacement of materials in flexible pavements. Key word: Recycled asphalt pavement aggregate, bitumen and waste water plastic bottles (PET)