In an ethnically homogeneous men population living in Tuscany, Italy, the relationship between age, height, body weight and bone mineral density were studied. In 50 men bone mineral density was measured by Dual Energy X ray Absorptiometry (DEXA). 13 subjects (26%) were osteoporotic. Age and bone mineral density were not related (R2 = 0.052). Bone mineral density was associated with body weight (R2 = 0.303), and height (R2 = 0.155). In osteoporotic men, mean (+/- SD) body weight was Kg. 65.8 +/- 11.2, lower than that recorded in non osteoporotic men, Kg. 77.3 +/- 10.2, (p = 0.0013). Age in osteoporotic and non-osteoporotic men did not differ (53.8 +/- 13.6 yrs and 60.9 +/- 11.8 yrs, respectively; p = 0.077). In conclusion, anthropometric factors, as predictors of bone disease, behave differently in women and men.