Abstract Fluoride levels were measured in Arctic char (Salvelinus alpinus) living near Narsaq. The Narsaq River is unpolluted, but has naturally high levels of fluoride—varying from about 2 mg/L in summer to 10 to 20 mg/L in winter. The river has a relatively large population of Arctic char which appears unaffected by the high fluoride level. Stationary char accumulate fluoride in muscles (16.6 mg/kg) and bones (1,150 mg/kg), while char caught in the estuary have concentrations similar to char from reference areas (6.5 mg/kg in muscle, 439 mg/kg in bone). It is concluded that Arctic char accumulate fluoride when living in the high-fluoride freshwater environment, but that concentrations return to normal in anadromous char during the 1 to 2 summer months annually spent at sea.