Heed: Kristen Amesen, M.D.Pituitary weight variation was studied in a consecutive autopsy series of 170 men over 40 years of age, among whom none had clinically manifest prostatic carcinoma or had previously been subjected to prostatic surgery. Among several factors tested by multiple regression analysis, a statistically significant and positive correlation between pituitary weight and body length only was demonstrated. Patients with a histalogically normal prostate showed a significant decrease of pituitary weight with advancing age, the weight being maintained to a larger extent in patients with benign hyperplasia and neoplasia of the prostate. I n the 7th decade of life, patients with benign hyperplada and carcinoma accompanied by hyperplasia showed significantly higher pituitary weights than normal controls. The results from the multiple regression analysis indicated that pituitary weight as such cannot be used to discriminate between various forms of prostatic histology.