We evaluated organic pollution in Bosten Lake, Xinjiang, China, by measuring the concentrationsand distributionsof organochlorine pesticides (OCPs) and polycyclic aromatic hydrocarbons (PAHs). Water and sediment samples were collected from 19 sites (B1-B19) in the lakefor analysis. Our analytical results show that the concentrations of total OCPs in water rangesfrom 30.3 to 91.6 ng/L and the concentrations of PAHsrangesfrom undetectable (ND) to 368.7 ng/L. The concentrations of total OCPs in surface (i.e., lake bottom) sediment rangesfrom 6.9 to 16.7ng/g and the concentrations of PAHs rangesfrom 25.2 to 491.0 ng/g. Hexachlorocyclohexanes (HCHs) and dichlorodiphenyltrichloroethanes (DDTs) account for large proportions of the OCPs. Low α- to γ-HCH ratios in both water and sediment samples indicate possible contributions from both industrial products and lindane. DDTs in water are probably from historical input, whereas DDTs in sediments are from bothhistorical and recent inputs. Moreover, DDT products in both water and sediments were from multiple sources in the northwestern part of the lake (B11, B12, B13, and B14). Fugacity ratios for DDT isomers (p,p′-DDEand p,p′-DDT) at these sites were generally higher than equilibrium values. These results suggest that the input from the Kaidu River and diffusion of DDTs from the sediment to the water are responsible for DDT pollution in the water. Lower-molecular-weight PAHs, which originate primarily from wood and coal combustion and petroleum sources, represent the major fraction of the PAHs in both water and sediment samples. Our findings indicate that OCPs and PAHs in BostenLake can be attributed primarily to human activities. A risk assessment of OCPs and PAHs in water and sediment from BostenLake, however, suggests that concentrations are not yet high enough to cause adverse biological effects on the aquatic ecosystem.