We have measured the levels of Fe, Cd, Ni, Pb and Co in zooplankton collected from Chemagari creek of Sagar Island of Hooghly estuary. Among the metafs studied Fe showed maximum concentration, The concentration of Pb and Co was below the level of detection limit throughout the season. The concentration of Fe, Cd and Ni in zooplankton varied from 1470 to 12051 ppm, 6 to 96 ppm and 4 to 29 ppm respectively. Negative correlation of Fe and Cd with salinity and pH of the habitat water is indicative of their source from upstream of the river.