The 1989-1990 Pesticide Reconnaissance Survey was conducted by the U.S. Environmental Protection Agency Region 10, Office of Coastal Waters and the Puget Sound Estuary Program to assess the extent and toxicological significance of water-soluble and sediment-bound pesticide residues present in Puget Sound drainages. Fifteen water samples and six sediment samples were collected from five drainage areas that empty into Puget Sound and analyzed for 33 different pesticide residues. Five pesticides were detected in at least one water sample: diazinon, 1,4-dichlorophenoxyacetic acid (2,4-D), dicamba, bromacil and diuron. The most commonly detected pesticide was 2,4-D which was detected in 13 water samples at concentrations from 0.077 to 0.70 micrograms/liter. Four pesticides or their degradation products were detected in at least one sediment sample: dichlobenil, pentachlorophenol, DDT/DDE/DDD and endosulfan I and II. Pentachlorophenol was detected in all six sediment samples at concentrations up to 33 micrograms/kg.