The effect of age and gender on 38 chemical element contents in femoral neck of 85 apparently healthy 15-55-year-old women (n = 38) and men (n = 47) was investigated by instrumental neutron activation analysis. Mean values (M +/- SEpsilonMu) for mass fraction (on dry weight basis) of Ca, Cl, Co, Fe, K, Mg, Mn, Na, P, Sr, and Zn for both female and male taken together were: Ca 153 +/- 3 g/kg, Cl 1,188 +/- 48 mg/kg, Co 0.0039 +/- 0.0004 mg/kg, Fe 55.5 +/- 8.8 mg/kg, K 490 +/- 22 mg/kg, Mg 1,940 +/- 48 mg/kg, Mn 0.385 +/- 0.015 mg/kg, Na 3,850 +/- 70 mg/kg, P 73.0 +/- 1.5 g/kg, Sr 288 +/- 18 mg/kg, and Zn 55.5 +/- 1.6 mg/kg, respectively. The upper limit of mean contents of Cr, Cs, Eu, Hg, Rb, Sb, Sc, and Se were: Cr < or = 0.2, Cs < or = 0.02, Eu < or = 0.007, Hg < or = 0.006, Rb < or = 0.8, Sb < or = 0.02, Sc < or = 0.0004, and Se < or = 0.06 mg/kg, respectively. In all bone samples, the contents of Ag, As, Au, Ba, Br, Cd, Ce, Gd, Hf, La, Lu, Nd, Sm, Ta, Tb, Th, U, Yb, and Zr were under detection limits. The Ca, Mg, and P contents decrease with age. Higher Ca, Cl, K, Mg, Mn, Na, and Sr mass fractions are typical of female femoral neck as compared to those in male bone.