Present study was carried out during the year 2007 to 2010, to describe the polychaete species in the Chilika lake after opening of a new lagoon inlet. A total of 45 polychaete species from the lake was observed. Among the dominant species Nereis reducta, Capitella capitata, Heteromastus filliformis, Minuspio cirrifera were conspicuous. Similarly, the taxa recorded first time in the lake were Amphictene auricoma, Spiophanes bombyx, Mediomastus, Pomatoceros caeruleus, Hydroides elegans, Pisione remota, Hesione picta, Eteone picta, Eumida sanguine, Bipalponephtys cornuta. These species were typical marine forms. This might be possible due to the opening of a new lagoon inlet. However, few indicator species like Capitella sp., and Minuspio sp. were observed from northern sector. From the entire study it was evidenced that sandy substratum of outer channel area appeared as the most suitable habitat for proliferation of benthic polychaete taxa.