A systematic study was performed on the effectiveness of plastic deformation in tension and compression relief of residual stresses derived from the rapid quenching of 7075 aluminum. Maximum stress relief was observed after about 1.4% deformation in tension and 1 % deformation in compression. Complete stress relief could not be obtained from either mode of deformation. Stress relief was found to be more effective after deformation in tension than in compression. Significant differences in types and levels of residual stresses were found in specimens deformed seemingly uniform in compression when measured on a free surface, or on one in contact with the platen applying the compressive force. The effect of artificial aging as a supplement to mechanical stress relief also was investigated. The practical implications of the results, particularly with respect to forgings, are discussed. Recommendations are made for further work.