The problem of relationships between the ultra-trace element content in a human organism and obesity has been poorly studied thus far. The primary objective of the current research has been to investigate the association between hair ultra-trace element content, body mass index and age in adult women. 1281 adult women participated in the survey. Hair ultra-trace element content (Ag, Au, Ga, Ge, La, Pt, Rb, Sb, Tl, W, Zr) was assessed by inductively coupled plasma mass spectrometry using a NexION 300D+NWR213 apparatus (Perkin-Elmer, USA). No significant association between the hair Ag, Au, Ga, Ge, La, and Pt content and body mass index (BMI) values was observed. The hair Rb levels in normal weight, overweight and obese women exceeded the respective values in underweight females by 33 (p < 0.001), 105 (p < 0.001), and 314% (p < 0.001). The hair Sb content in obese persons was 38 (p < 0.001), 38 (p < 0.001), and 22% (p = 0.022) higher in comparison to the values observed in underweight, normal weight and overweight subjects. A twofold increase in the hair Tl content was observed in obese females in comparison to the underweight (p < 0.001) and normal weight ones (p = 0.037). It has been observed that obese women were characterized by 33% higher hair W levels in comparison to the underweight (p < 0.001) and normal weight group values (p = 0.002). The results of correlation and multiple regression analyses partially confirmed these findings and indicated that hair Rb values were characterized by the closest association with the age and BMI. To our knowledge, it is the first report on a relationship between the hair ultra-trace element content and increased body weight. The data may be used as reference values of the content of ultra-trace element in hair of women with different body mass index. However, additional experimental and clinical studies are required to explore the mechanisms of such an association.