The level and distribution of chromium (as total chromium and CrVI) and other trace elements were investigated from surface and groundwater samples collected over three periods (n = 155) from Mersin (Turkey) in terms of their origins and potential health risk. The maximum total chromium is 41 mu g/L and some of the samples have CrVI contents above 5 mu g/L, which is the maximum permissible level of CrVI under Italian regulations. The dominant water facies are Ca-HCO3 and Mg-HCO3 types based on the Piper diagram. The Ca-HCO3 type waters originate mainly from interaction with carbonate rocks, and the Mg-HCO3 type waters originate from serpentinite dissolution. Chromium contents are higher in Mg-HCO3 water types and the highest concentrations are found in samples from ophiolitic rocks and industrial areas. The As, Fe, Pb, Al, and Ni contents of some samples are above the EU limits in industrial areas.