In order to gain better understanding of the effect of pre-aging on the tensile properties of 6201 Al alloy, different TAHA processes have been performed in this study. A 6201 AI alloy was first solution treated, followed by pre-aging at 135°C for 30 minutes (some specimens were without pre-aging). The specimens were then cold rolled to 60, 70 or 80% reduction in thickness followed by final aging at 140, 150 or 160°C for 1 to 20 hours. For specimens of 60% cold reduction, the ultimate tensile strength (UTS) and yield strength (YS) were significantly improved by pre-aging. The improvement in strengths by pre-aging was most (least) significant if the final aging temperature was 140°C (160°C). For specimens of 70% reduction, the improvement in UTS and YS by pre-aging was not as significant. For specimens of 80% cold reduction, lower strengths were found for pre-aged specimens as compared to specimens without pre-aging. Scanning electron microscopy revealed that there was close relationship between the fracture morphology and the resulting tensile properties. Proper combination of pre-aging and cold work led to finer, denser and more uniform distribution of precipitates which resulted in better tensile properties