Obesity, the most frequent nutritional problem throughout the rich nations, can have a vast and significant influence on different aspects of endocrinology, in particular on ovulation disfunction, on hyperandrogenemia, on hormone-sensitive carcinomas. Our study proposes to value the response to adrenal cortex to stimulation with adrenocorticotropin (ACTH) hormone in obese patients, with particular attention to the behavior of adrenocortical androgens and their precursor. We recruited 30 female patients so divided: 12 obese, nonhirsute, eumenorrheic patients (group A); 10 normal weight, hirsute patients in situation of secondary amenorrhea (group B); 8 normal weight, nonhirsute, eumenorrheic patients (group C). Cortisol, progesterone, 17 OH progesterone, dehydroepiandrosterone sulfate, androstenedione, testosterone were measured at 60, 120, 180, 240, 300 min during continual infusion i.v., for 5 h, of ACTH 1-17 at 100 mcg dose, in physiological sodium chloride solution. All the women with monthly menstruation were studied between the IV and VIII day of their cycle. In the patients with secondary amenorrhea the value of basic progesterone was used to completely exclude an eventual luteal phase and the relationship LH/FSH was so as to logically exclude a diagnosis of polycystic ovary. This exclusion was also confirmed from the report of the ultrasonography. The basic concentration of hormone dosage is not significantly different between the patients of the three groups, except for T. This hormone is different because it is found to be significantly (p < 0.01) increase in the hirsute patients, in respect of the patients in group A and group C. Also P and 17OHP have been found to be higher, if only in insignificant measure, in hirsute patients.(ABSTRACT TRUNCATED AT 250 WORDS)