An endocrinological study of 15 psychiatric patients with primary cutis verticis gyrata (CVG) and 7 control patients was carried out. The investigation of the pituitary-gonadal axis, pituitary-adrenal axis, pituitary-thyroid axis, prolactin and human growth hormone (basal values and circadian biorhythms) did not show any significant difference between the CVG and the control patients. Only levels of free testosterone were significantly lower in patients with CVG than in the control group (p < 0.05), probably reflecting an increased peripheral use of testosterone.