This study was conducted to investigate the mechanical properties and water absorption of geopolymer modified bitumen. Modification of 80/100 penetration grade bitumen with the 3, 5, 7 and 9% geopolymer (by weight of bitumen) were conducted using a melt blending technique. The study of mechanical properties of geopolymer modified bitumen was conducted using impact and hardness tests. On the other hand, water absorbed behaviour of bitumen was investigated using water absorption test. The results showed that the modification of base bitumen using geopolymer has increased the strength and hardness of binder up to 108% and 82% compared to the base bitumen. The absorption amount recorded by geopolymer modified bitumen can be considered as acceptable. This study found that 5% geopolymer is the optimum content of the modifier. Therefore, geopolymer can be considered as an alternative material to modify the mechanical properties of bitumen.