The alloy composition of Al-33.33 at% Cu (Al-54.15 wt% Cu) was selected for the present research. The effect of the milling duration on the synthesis of Al2Cu intermetallic compound was analyzed using several analytical techniques like XRD, SEM, EDX, HRTEM, and DSC/TGA. Nanostructured Al2Cu was successfully synthesized by mechanical alloying (MA) of Al-33.33 at% Cu powder for more than 15 h followed by annealing of the milled powder in Ar atmosphere at 1000 °C for 2 h. Residual Al and Cu powder that has not been transformed to Al2Cu were found in the milled powder even after 20 h of milling. Rietveld analysis was done for a better understanding of the phases evolved during MA and the annealing of the milled powders. The synthesis of the nanostructured intermetallic compound Al2Cu by MA followed by annealing of the milled powders was confirmed by analysis of the powders using various techniques.