The Point Calimere Wildlife and Bird Sanctuary (PCWBS) in Tamil Nadu was declared a Ramsar site No. 1210 in 2002. The PCWBS consist of shallow waters, shores, and long sand bars, intertidal flats and intertidal forests, chiefly mangrove, and seasonal, often-saline lagoons, as well as human-made salt exploitation sites. It is famous for large congregations of waterbirds and is rich in both resident and migratory species of birds. These migratory and resident birds are dependent on plants. Birds retreat to trees and bushes as protection from predators and to rest and roost. Plants provide all the foods that birds eat and some species also nibble nutritious plant buds or sip flower nectar. Many birds construct nest on trees and lay their eggs on plants. Tree population in Point Calimere is crucial for birds and animals. Hence the present study made an attempt to record the tree species diversity in Point Calimere Wildlife and Bird Sanctuary, Tamil Nadu. The Point Calimere has a total of 91 tree species. They belong to 73 genera and 38 families. Family Fabaceae is the most dominant with 14 genera and 21 species. Species such as Commiphora berryi and Dalbergia horrida are the common peninsular endemics. Totally fifty tree species are used to treat various ailments. Major threats to the natural biodiversity and ecological balance of the sanctuary are: loss of habitat for waterbirds, soil and water salinisation by adjacent salt pans, spread of the invasive Prosopis chilensis, cattle grazing and scarcity of fresh water.