Puttalam Lagoon and the surrounding sea area in Sri Lanka have been well known for its diversity of birds. The area consists of many habitats including mud flats, sand bars, mangroves and marshes. As many migrant birds enter the island from this area, the diversity is high during the migratory season. The area is to be developed into a tourism hotspot and organized bird tours are carried out by several organizations for tourists in this area. Thus, a survey, was carried out in the study area, which included the land areas and the lagoon area, in November 2013 for its avifauna in order to prepare a preliminary checklist of birds useful for eco-tourism covering the sand bars, islands, lagoon area and adjacent land area. Fourteen sampling sites were visited in the morning between 6.30 am and 10.30 am and in the evening between 3.00 pm and 6.00 pm. Observations were made using binoculars 8 x 40 and 10 x 50. A total of 89 species of birds were encountered during this survey while only 24 migrant species were observed. The sea birds observed on the sand bars close to the northern tip of the Kalpitiya Lagoon were Gulls and Terns. Four species of Gulls were recorded from this area dominated by Larus brunnicephalus. Terns belonged to seven species including four migrant species. Shore bird species were dominated by plovers. Although the area is known for many pelagic sea birds, no special birds were observed during the survey. Over 30 individuals.of Pelecanus philippensis were found in the lagoon, which was the only globally threatened species observed during the survey. This is an important observation as the numbers of this bird observed in other regions of the world are low. As this was a preliminary study, the area needs to be surveyed extensively during the migrant season to prepare a more detailed check list. Flowever, the results of this survey showed that the study area has a high diversity of birds and would be a promising area for development of ecotourism.