Background & Aims : Right branch of Sarugh River is the main river in Takab city, north western Iran, which is located at downstream of present gold extraction plants. Cyanide leak aging from tailings dams of plants is a serious threat to the health of river. This study was conducted to evaluate Cyanide concentration and transferring cyanide to the river.

  Materials & Methods : In this cross sectional study, total Cyanide with some parameters such as dissolved oxygen, ph, turbidity, temperatuer, total dissolved solids, electrical conductivity, nitrate, ammonia and sodium measured monthly at 5 stations located along the river during spring and summer 2011. Cyanide concentration was determined in the station and compared with standard level (0. 07mgl^-1). Cyanide concentration along river at sampling stations was zoned by ARC GIS 9.3.

  Results : In the stations located at upstream plants, the Cyanide concentration was below the detection limit (0. 002 mgl^-1). The highest concentration of cyanide (0. 28 mgl^-1) and soduim (74. 94 mgl^-1) were at station C(downstream of Puya Zarkan plant). The cyanide concentration had sudden drop at station D (downstream of Pars Kani plant). Average concentration of cyanide in high- water season was higher than the low-water season.

  Conclusion : As results showed precipitation can cause to discharge the contents of the Pars Kani tailings dam into the river. Results showed the concentration of Cyanide along the river in sampling stations near gold extraction plant was higher than the standard levels and it is necessary to control leakage from the plants.