The aim of this study is to investigate the levels of bacteriological water quality and pollution in Yağlıdere Stream, Giresun, Turkey. For this purpose, surface water and sediment samples were collected monthly, from five stations between June 2013 and May 2014. A bacteriological assessment of water and sediment samples with a 22 °C to 37 °C temperature range, including total coliform bacteria (TC), fecal coliform bacteria (FC), fecal streptococcus (FS), and Escherichia coli were done. Analysis was performed according to standard methods. Water quality and pollution level in Yağlıdere Stream were assessed in accordance with both Turkish legislation and international criteria. The FC, FS and E. coli count were detected higher than the reference value at multiple stations in almost every month of the year indicates. In conclusion, it can be said that the bacteriological pollution level of both the surface water and sediment structure of the stream pose a threat to the ecosystem balance.