The trophic ecology of Liza grandisquamis in Bonny River, Niger Delta, Nigeria, was investigated over a period of ten months. Primary dietaries were fine particulate organic matter, mud and diatoms. Coarse particulate organic matter, sand, bluegreen, red and green algae, dinoflagellates, microarthropods, foraminiferans and nematodes were of secondary importance. Variations in food habit according to fish length, months and seasons are presented. Furthermore, the effects of two hydro-meteorological factors (rainfall, salinity) on food habits are given.