Abstract: To ascertain the ecological state of Badagry creek, Lagos, Nigeria, some physico-chemical parameters, heavy metals concentration in water and bottom sediments were analyzed and its fish composition determined. Monthly values of temperature, pH, acidity, turbidity, salinity, TDS, COD, NH3 and NO3 were significantly different over a period of six months (p< 0.05). There were no significant variations in colour, alkalinity, BOD, DO and PO4 values with the sampling periods. However, colour, temperature, alkalinity, BOD and COD values were significantly different across the sampling stations. Higher values obtained for BOD and COD at Station D (Ajido) than other stations suggests anthropogenic organic loadings on this axis of the creek. Salinity values showed highly significant correlation with TDS, BOD and COD and equally revealed Badagry creek as an estuary. N:P ratio was not statistically significant across the stations and sampling periods. Heavy metals (Hg, Ni, Cr, Cd, Ar and Se) concentrations were Not Detected (ND) in water. With the exception of Cu, there were no significant variations in other heavy metals concentration with the sampling stations, however, within the sampling periods, only Cu and Mn showed no significant variation in concentration. Bottom sediments concentrations of heavy metals (Fe, Cu, Cr, Pb, Mn and Ni) and (Cd, Pb, Fe and Ni) were statistically significant with the sampling periods and sampling stations respectively. Mercury (Hg) was not detected. Biological survey of fish species yielded 1614 samples of the fish population comprising 28 families, 34 genera and 37 species. Percentage relative abundance of species was highest for Chrysicthys nigrodigitatus (15.74%), Ethmalosa fimbriata (15.55%) and Tilapia zilli (8.55%).