This paper investigated the effect of niobium on the structure and mechanical properties of aluminium bronze. The properties studied were ductility, tensile and yield strengths, using universal testing machine model 50kN, impact strength using charpy machine model IT-30 and Brinell tester model B 3000 (H). The specimens were prepared by doping 1- 10% niobium into aluminium into the aluminium bronze (Cu-10% Al) at interval of one percent. The specimens were prepared according to BS 131-240 standards. Microstructural analysis was conducted using L2003A reflected light metallurgical microscope. Results obtained shows that tensile strength, yield strength, impact strength and ductility increased by 10% respectively. 1% niobium shows increased in hardness result. Microstructural analysis revealed the primary α-phase, -phase (intermetallic phases) and fine stable reinforcing kappa phase and these phases resulted to the enhanced mechanical properties. Aluminium bronze doped with niobium proved to increased strength, ductility, and impact strength and reduces hardness and is therefore recommended for applications in engineering and allied industry.