We investigated concentrations of calcium, copper, iron, magnesium, potassium, sodium and zinc using atomic absorption spectroscopy in the hair of four groups of adult females (n = 392), ranging in age from 20 to 50 years, with different body mass index (BMI): BMI < 18, slim group; BMI 18-25, normal group; BMI 26-35, overweight or obese group; and BMI>35, morbidly obese group. We found that the group with BMI < 18 had the highest ratios for [Ca]/[Mg], [Fe]/[Cu] and [Zn]/[Cu], but the lowest ratio for [K]/[Na] in hair. On the contrary, the group with BMI > 35 had the highest ratio for [K]/[Na], but the lowest for [Fe]/[Cu] and [Zn]/[Cu] in hair. Furthermore, when we compared concentrations of Ca, Cu, Fe, Mg, K, Na and Zn between the groups with BMI < 18 and BMI > 35, we found that there were significant differences (p < 0.05) in zinc concentrations between these two groups. In addition, there were significant differences in Ca, Cu, Mg, K and Na concentrations, with p < 0.01 at least. From this point of view, we suggest that hair concentrations of Ca, Cu, Fe, Mg, K, Na and Zn may be correlated with adult female BMI, but further studies are needed.