he increase in the amount of reclaimed asphalt pavement (RAP) and environmental concerns for bitumen production have contributed to the  use of RAP in road construction and maintenance.  The  use  of  higher  than  15%  of  RAP  adversely  affects  the  physical  and rheological  properties  of  the  asphalt  binder  and  the  mechanical  properties  of  mixtures. Therefore,  the  use of bitumen  and  asphalt  mixture  improver  were  necessary  to  reduce  the negative  effects  generated with  the use  of RAP.  This  paper  aims  to  study  the  effect  of fiberglass (FG) (0.5%,  1.0%, 1.5%,  and 2%) on the  mechanical  properties of asphalt concrete containing  25%,  50% RAP and  9%  waste  engine  oil. The  performance  of  RAP  asphalt mixtures  incorporated  with FG was evaluated using  the Marshall  stability test,  moisture susceptibility  test,  and immersion wheel rutting  test. The  results indicated that the  use  of FG and  RAP  materials  to  rejuvenated asphalt  mixtures resulted  in  an increase  in  the values  of Marshall  stability  and  rutting  resistance. Moreover,  the  study revealed that  increasing  the content of RAP material and FG results in increased resistance of asphalt to moisture damage. This paper concluded that using 0.15% of FG and 50% RAP materials gives the best results