Artisanal Small Scale Gold Mining has affected environment, since the gold processing method released mercury into the environment. Contaminated water was used as drinking water and could be the route of mercury entered human body. Kidney  was one of mercury target organ. Mercury poisoning signs depend on nature of mercury, dose, route, duration of exposure and age of host. The objective of this research was to find out mercury pollution in drinking water and its effect on renal function of children in ASGM area Sekotong in West Lombok. This preliminary study design was cross sectional. The study was conducted in ASGM area Sekotong subdistrict. Sample of drinking water collected from various sources which located ASGM area. Mercury concentration was assessed by using AAS. Renal function of school age children were evaluated from urine sample by using  dipstick kit. Correlation between contaminated water consumption and renal function was analyzed statistically by Spearman’s test. Concentration of mercury found in water samples taken from well was 4.009 ppb, while  water sample from wellspring water was 0.724 ppb and 0 ppb from pipe water samples. From 15s samples, 12s samples had higher value than mercury threshold for drinking water. Two of 30 school age children were positive proteinuria. Correlation between mercury contaminated water and proteinuria analyzed by Spearman’s test showed p value of 0.000. Drinking water in ASGM subdistrict Sekotong West Lombok has been contaminated by mercury and affected kidney function of school-age children.