This study presents an investigation on the role of temperature on the failure of diffusion-bonded Aluminium and Nickel. During diffusion bonding processes, where the bulk materials is subjected to join at the temperature of 300 K, 500 K, and 700 K with pressure of 10 MPa for 200 ps, the applied temperature is significantly influencing the final result of diffusion-bonded Al-Ni both in term of qualitative analysis (diffusion behaviour) and quantitative calculation (concentration distribution). In this case, as the temperature increased, the thickness of the interfacial region/diffusion zone is increased. However, when it is subjected to tensile test, the applied temperature is only has a significant impact to the ultimate tensile strength, that as the temperature is increased the ultimate tensile strength is decreased, but the applied temperature during diffusion welding is not influencing both time and strain value of the sample when it starts to failure.