Bioaccumulation of Polybrominated Diphenyl Ethers (PBDEs) was investigated in sediment and tissues of the Oyster (Crassostrea tulipa) from Unilag Lagoon Front, Makoko and Oworonshoki sampling stations within the Lagos Lagoon, Nigeria using Gas Chromatography coupled with Electron Capture Detector (GC-ECD). The samples collected were analyzed for PBDEs congeners of BDE 28, 47, 99, 100, 153, 154, 183 and 209. The results of the mean concentration of PBDE congeners detected in sediment and Oyster tissue were BDE 28, 47,183 and BDE 28, 47, 153 respectively, in all sampled stations, which was significantly higher (P < 0.05) comparing with Canadian Federal Environmental Quality Guidelines for PBDEs. Oworonshoki station had the highest concentration of total PBDEs (600.07 ng/g dry weight) while Unilag (386.43 ng/g dry weight) had the least concentration. BDE 28 was detected highest in all stations while congener BDE 183 was lowest in concentration. BDE 28 (70%) was the only congener distributed in the Oyster and sediment samples collected from all the stations and was significantly higher when compared with the Federal Environmental Quality Guidelines for PBDEs. Total PBDE concentration in Oysters showed that Oworonshoki had the highest concentration (615.44 ng/g) while Makoko showed the least (336.22 ng/g). The Biota Sediment Accumulation Factors for BDE 28 (1.181) and BDE 47 (4.990) were greater than 1, an indication of bioaccumulation. The present study established a reflection of the environmental health of the selected sampled areas and therefore, a useful tool for monitoring of PBDEs pollution.