This paper presents a comprehensive evaluation of drinking water quality from the stream Galyan and its tributary, the stream KuAYtul, in Trabzon Province, Turkey. In this study, surface water quality data for 20 physical and chemical parameters were determined and collected from three monitoring stations of the understudy stream during April 2004 to March 2005. According to the Turkish Water Pollution Control Regulation, the stream Galyan water was classified, and the studied parameters were evaluated for the values proposed by Turkish Standard (TS) 266 and World Health Organization (WHO) guidelines. The results showed that TS 266 and WHO guidelines were exceeded for Fe (up to 860 mu g/l) and Cr (up to 134.7 mu g/l). Pearson's correlation was also used to determine the relationship of the studied parameters and as a result significant correlations were observed between some parameters.