The aim of the study was to assess elemental composition of hair of residents of the Khanty-Mansiysk Autonomous Okrug (Khanty-Mansi Autonomous Okrug) living in cities with different quality of drinking water. Methods. The elemental composition of hair was studied in 84 residents of Surgut and Khanty-Mansiysk cities with high-quality drinking water water, and in 71 residents of Nefteyugansk and Nyagan - cities with low-quality drinking water. The concentration of 25 chemical elements in the hair including iron (Fe), manganese (Mn), calcium (Ca), magnesium (Mg), copper (Cu), zinc (Zn) and selenium (Se) was assessed using atomic emission spectroscopy (AES-ICP) and mass spectrometry (MS-ICP) with inductively coupled argon plasma on Optima 2000 DV and ELAN 9000 instruments at the INPO "Center for Biotic Medicine" (Moscow). Data were analyzed using MS Excel and STATISTICA 8.0. Results. Significantly higher concentrations of Fe and Mn (p < 0,001) and lower concentrations of Se (p = 0,012) were revealed in the hair of residents of cities with low-quality drinking water. The concentration indices of Ca, Mg, and Cu in all cities were similar. The prevalence of Zn and Se deficiency in cities with low-quality drinking water was 1.5 and twice as high compared to areas with high quality drinking water. Conclusions. Residents of cities with low quality drinking water have less favourable concentrations of studied elements in hair. This may be associated with lower antioxidant protection which in turn may be associated with greater prevalence of chronic diseases in these cities.