Water supply from boreholes is today used by people from rural areas of Turkey more com- monly due to the reduction of available surface water. For this reason, the concentrations of Al, As, B, Be, Ca, Cd, Co, Cr, Fe, Hg, K, Mg, Mn, Mo, Na, Ni, Pb, Se, Sn, and Zn in borehole waters of the Diyarbak?r province (SE Ana- tolia) were determined in this study. Thirty borehole waters were sampled from different towns and villages. The samples were analyzed by inductively coupled plasma optical emission spectrometry (ICP–OES). The results of the analyses were com- pared with guidelines as set by Turkey, the WHO, and the EU. From the results it could be con- cluded that the ICP-OES method can be considered useful for the routine determination of trace elements in waters and similar matrices. For quality control pur- poses, the certified reference material TMDW-B Drinking Water was employed for valida- tion. The recovery values were in the range of 93–101%. The Al, As, B, Be, Cd, Co, Cr, Hg, Mn, Mo, Ni, Pb, and Sn concentrations in the samples were found lower than the recommended LOD. The concentrations found were in the range of 12.71–111.4 mg/L for Na, 0.76–3.07 mg/L for K, 9.62–115.5 mg/L for Ca, 2.69–41.85 mg/L for Mg, 10 μg/L.