SUMMARY: A hypothesis by Ravich and Ravich (1951) that carcinoma of the prostate is rarer in men who have been circumcised in infancy is discussed. A series of 105 cases with histologically proven carcinoma of the prostate has been examined in relation to the state of the foreskin. Twenty per cent. had been circumcised in infancy. A series of benign and malignant neoplasms of the prostate has been reviewed and 4.2 per cent. of cases with prostatic cancer were Jewish (approximately the figure calculated for the general Jewish population in the age group of the disease).