Zooplankton are known as good bio-indicator of changes in water quality because it is strongly affected by any changes in physical and chemical conditions of water as well as the surrounding environmental condition. Zooplankton diversity and physico-chemical parameters of an oxbow lake, Madhura anua was studied for a period of one year from September 2012 to August 2013. During the study period a total of 26 species belonging to 4 groups of Zooplankton were recorded of which rotifera was represented by highest number of 16 species, Cladocera by 7 species, copepoda by 2 species and ostracoda by only 1 species showing lowest percentage of presence. Zooplankton community when correlated with physico-chemical parameters indicated that Dissolved Oxygen and free Carbon Dioxide are significantly inversely correlated (p < 0.01) with the occurrence of zooplankton.