Estrogen treatment of postmenopausal women has been suggested to improve mood and psychological function. However, this remains controversial because previous studies involved heterogeneous groups, were not double blind, and included women who were also experiencing somatic symptoms that were relieved by estrogen. A randomized double-blind study was carried out comparing the effects of placebo and conjugated equine estrogens (0.625 and 1.25 mg) on psychological function over 3 months in 36 asymptomatic women, aged 45-60. The tests included the Minnesota Multiphasic Personality Inventory-168, the Profile of Adaptation to Life, and the Beck Depression Inventory. Memory was assessed directly by the Wechsler Adult Intelligence Scales, measuring both digit span and digit symbol. All women were well-adjusted psychologically. The income management scale of the Profile of Adaptation to Life improved (P less than .05) with estrogen, as did the Beck Depression Inventory (P less than .05), but these results were not dose-related. Memory assessed prospectively by the Wechsler Adult Intelligence Scales was not affected significantly. These results suggest that estrogen use may improve the overall quality of life in postmenopausal women.