Human anterior pituitary glands collected at autopsy within 6 hours of death were investigated for gonadotrophic and lactogenic activity. The glands were extracted with 2% saline and most of the gonadotrophic and lactogenic activity appears to be extracted by this procedure. Little corticotrophic and thyrotrophic activity was found in the extract. The yield of extractable gonadotrophin in the pituitary glands of males and females of varying ages, and the effect of ovariectomy (in two cases) and of cortisone therapy (in one case) on the yield have been investigated. A reference preparation for human menopausal gonadotrophin (HMG20A, Organon) was used as a standard. The amount of stored gonadotrophin increased with advancing age in both sexes. Ovariectomy was associated with a higher yield and cortisone therapy with a lower yield than that shown in pooled pituitary glands from women of the same age group. The ratio of the biological activity of FSH to ICSH in the pituitary glands of men over the age of 50 was about 1:1. The method of assay for prolactin was semi-quantitative but there was the same general trend of increased yield with advancing age. The pituitary gland from the case treated with cortisone had the highest yield while ovariectomy appeared to result in a decrease in the stored amount of the hormone. The functional significance of the results of the yield of stored hormones in the human pituitary gland is briefly discussed.