The influence of cigarette smoking, body iron store status and gender on cadmium (Cd) body burden was examined in a group of 197 healthy Thais with overall mean age of 30.5 year (19-47 year). The lowest, geometric mean, and the highest urinary Cd excretion rate was 0.04, 0.46 and 3.84 microg/g creatinine, respectively. The prevalence of low iron stores (serum ferritin <20 microg/l) was 16% and 2% in women and men, respectively. All women (n = 99) were non-smokers, but they had the same Cd body burden as did men (n = 47) who on average smoked 8.7 cigarettes per day for 9 years. These women and men had 1.9-fold greater body Cd burden than did non-smoking men (t = 4, P < 0.001). In addition, the women Cd body burden was found to be inversely correlated with serum ferritin (r = -0.39, P < 0.001) and those with low iron stores showed a 3.4-fold greater Cd body burden than did women whose serum ferritin being between 101 and 200 microg/l (F = 6.2, P = 0.003, one-way ANOVA). In contrast, men's Cd body burden did not show a significant correlation with serum ferritin, but it did show a positive correlation with cumulative cigarette smoking index (r = 0.29, P = 0.02). Thus, iron status and cigarette smoking were found to be determinants of Cd body burden in young adult Thai women and men.