The aim of this study was to investigate the effects of incorporating recycled asphalt pavement aggregate (RAPA) and modified bitumen with waste plastic bottles on the Marshal properties of hot mix asphalt. Various experiments were carried out on the hot mix asphalt mix using recycled asphalt pavement aggregate and modified bitumen with different proportions of waste plastic bottles (5%, 10%, 15%, 20%, and 25% by weight). The findings revealed that with 10% modified bitumen, all specifications were met. Analysis of the test results indicated that recycled asphalt pavement aggregates completely replaced virgin aggregates, and a 10% modification of bitumen (80/100) with waste plastic bottles was suitable for designing flexible hot mix asphalt pavement that complied with the specifications.