Nailfold capillary microscopical and hormonal investigations were carried out in 25 patients with cirrhosis of the liver and in 20 age- and sex-matched controls. Several structural and functional capillary microscopical parameters were significantly different between the group of cirrhotics as a whole and the controls; no capillaroscopic feature helped to distinguish cirrhotics with spiders from those without. Serum estradiol and total testosterone were comparable in cirrhotics and controls; free serum testosterone was reduced in male cirrhotics, particularly in cirrhotics with spider nevi. The estradiol/free testosterone ratio was highest in male cirrhotics with spiders. Cirrhosis, thus, leads to both structural and functional effects on the cutaneous capillary system whether or not spider nevi are present. The presence of spider nevi is accompanied by an increased serum estradiol/free testosterone ratio in male cirrhotics. It remains to be determined whether the hormonal alterations described do indeed play a role in spider nevi formation.