In a number of endocrine disorders, typical changes in skin thickness can be observed which make measurement of skin thickness interesting in this field. A newly developed mechanical method for measuring skin thickness is presented. Using a digital measuring screw on the dorsum of the hand with a defined measuring force of 10 newton and a resulting tissue compression of 1500 mm Hg, highly reproducible results were obtained (mean coefficient of variation 2.56%). In 129 women, 37 to 78 years old, body mass index < 30 kg/m2, there was no significant relation between body mass index and skin fold thickness. A negative correlation between skin fold thickness and age (r = 0.37, p < 0.001) was detected. This has been shown for skin by other methods previously and is well known to occur in bone, another tissue whose matrix as well as dermis consists mainly of collagen type I. In 30 subjects, half hypopituitary patients, half healthy subjects (17 women, 13 men; 43.3 +/- 10.5 years old), skin fold thickness measured mechanically and sonographically determined skin thickness correlated with r = 0.46 (p < 0.01). A significant correlation between bone mineral density measured by single photon-absorptiometry at the ultradistal forearm and skin fold thickness measured mechanically was found and skin fold thickness measured mechanically was found (r = 0.36, p < 0.05), whereas this was not the case for sonographically determined skin thickness and bone mineral density (r = 0.13, n.s.). This newly developed method might be useful in clinical studies on endocrine disorders affecting skin (and bone) metabolism and the regulation of collagen type I metabolism in general.