In this study, some water quality parameters, chlorophyll a, phytoplankton abundance, composition and zooplankton abundance were investigated to determine the trophic state of the recreational pond of Sarisu over a period of six months. The trophic state of the pond was determined as mesoeutrophic-eutrophic with respect to water quality parameters, These parameters were discussed according to the Turkish Environmental Law. A total of 31 species belonging to Bacillariophyceae, Chlorophyceae, Chrysophyceae, Cryptophyceae, Cyanophyceae and Dinophyceae was identified during the study period. Phytoplankton numbers changed between 495000 and 12808000 cells/l while chlorophyll a concentration varied between 1,12 and 13,2 mg/m(3). Rotifera species was dominant in the zooplankton composition. Results are pointed out a rapid eutrophication in the pond and because of this nutrient increase must be controlled.