To examine age-related changes in body composition and testosterone (T) among men in an urban sub-Saharan African population, measures of body composition and salivary T were obtained from 109 males ages 20–78 in Harare, Zimbabwe. Measures included height, weight, suprailiac and triceps skinfold, and percent body fat by bioelectric impedance (BIA). Saliva samples were assayed for T using radioimmunoassay. Average BMI of the overall sample (23.16 (SD = 18.12) kg/m2 was close to Western populations, while salivary T levels (AM = 196 ± 96 pmol/l; pm = 172 ± 98 pmol/l) were much lower. Both morning (beta = –0.535; P < 0.001) and afternoon salivary T declined with age (beta = −0.385; P < 0.001). Multiple regression models indicate that pm salivary T (beta = 0.24; P = 0.025), was a predictor of fat-free mass, but neither am nor pm salivary T was related to fat mass or other measures of body composition. In addition, height was significantly related to pm salivary T levels in men under the age of 60. Multivariate regression indicates that pm salivary T is a predictor of fat-free mass when controlled for height and adiposity. These findings suggest that T is related to both lean mass and overall body size among men from a non-Western nonsubsistence population. As such they are consistent with the hypothesis that bioavailable T plays a role in energetic allocation among human males. Am. J. Hum. Biol. 16:704–712, 2004. © 2004 Wiley-Liss, Inc.