In this study, the influence of bothheat treatment and cold working (rolling) on the tensile properties andhardness of6061 aluminum alloy sheets was investigated. The solution heat treatment is first performed at about 520°C 1 hr followed by rolling to(40% and 60%). Artificial aging is obtained by heating to about 180 °C for 1/2hr and 2 hr.Theexperimental work has revealed that when two strengthening mechanism(cold work and aging)are combined, the values of the mechanical properties are come up.Increasing the aging time from ½ hrto 2hr with redaction in area was causing increase in the values of the strength and hardness and dropping the elongation. In the other hand, increasing the redaction in area from (40%) to (60%) with aging was rising the value of the strength and hardness and dropping the elongation. The changes in mechanical properties were discussed as a result of increasing the dislocation density(result of rolling) and formation of precipitation(effect of aging) which are interface with the motion of dislocation and causes hindering of dislocation.