The Cocos Island, Guam PEDs (polyethylene device) passive water sampler data set contains results of the analysis from Project 31181 funded by NOAA’s Coral Reef Conservation Program. The project involved NOAA National Center for Coastal Ocean Science, Guam Environmental Protection Agency and the United States Environmental Protection Agency. The data resulted from the deployment of an array of PEDs passive water samplers in the waters around Cocos Island in Cocos Lagoon, Guam. Duplicate PEDs were deployed at 26 sites by NOAA and Guam EPA personnel in September 2017, and then retrieved one month later by Guam EPA personnel. At 22 sites, the PEDs were deployed in the water column along six transects on the northwest shore of Cocos Island; an additional PED was deployed in the water column along the southeast shore. At two sites (9-1 and 9-2), PEDs were embedded in the sand along the shore, with the remaining PED (4-3 #035) embedded in the sand underwater at site 4-3. The duplicate PEDs from each site were combined and analyzed as one sample, in an effort to increase the sensitivity of the analysis (lower detection limit). The PEDs were analyzed for a series of organic chemical contaminants including polychlorinated biphenyls (PCBs), organochlorine pesticides and petroleum hydrocarbons (PAHs), all of which are contaminants of concern in the area. The polyethylene sheets comprising the PEDs at each site was analyzed, and the results are reported as nanograms of contaminant per each analysis, or ng/ea.