n0ne ; This study aimed to investigate the environmental risks of Total Mercury (THg) accumulation in Sentani Lake, Papua, Indonesia. THg was assessed around the Sentani Lake. Sampling survey for Water column, sediment, bivalve, pelagic and benthic fishes samples were collected in one time collection. Furthermore and potential environmental and health risks were determined using hazard quotient (HQ) and target hazard quotient (THQ) equation. Results revealed the concentration of Hg in water column, sediment, bivalve, pelagic and benthic fishes were ranged from 0.002 to 0.076 ??g L-1, 115 to 184 ??g kg-1 dw, 0.024 to 1.678 ??g kg-1 ww, 0.017 to 1.265 ??g kg-1ww and 0.139 to 1.845 ??g kg-1ww, respectively. The elevated values of Mercury concentrations were observed in sediment and benthic fish (at the maximum concentrations of 1.678 ??g kg-1dw and 1.845 ??g kg-1ww), respectively. The magnitude of environmental Hazard Quotient for water and sediment showed that 0.001 ??? 0.038 and 0.66 ??? 1.06, respectively. In addition, the high values of target hazard quotient (THQ) for water column, bivalve, pelagic and benthic fishes were in the range of 0.004 to 0.252, 0.005 to 0.190 and 0.024 to 0.277, respectively. All those levels have not exceeded the limit standard or