The effect of recombinant-DNA human growth hormone treatment on psychological well-being and quality of life was studied in adults with GH deficiency (GHD). 24 adults who satisfied strict criteria for GHD took part in a double-blind, placebo-controlled, 6-month trial. Quality of life assessments were performed at entry, 1 and 6 months by means of self-rating questionnaires. This study reports significantly lower scores on quality of life assessment in the GH-deficient patients at entry compared with matched controls, indicating that this population may be psychologically compromised. Preliminary analysis of treatment results shows that after 6 months, those patients receiving active treatment experienced less perceived illness than the placebo group. Significant psychological improvements were noted in the patients’ perception of their energy level and mood.