Abstract: Abidjan city, the economical capital is located in the estuarine part of the Ebrié lagoon. This part of the Ebrié lagoon as become the main receptacle of several discharges from industrial, agricultural, port and urban sewage. Surface sediments were collected from eighteen stations around Abidjan city in order to assess the catchment activities on organic matter and heavy metals inputs into the lagoon. Some important physicochemical parameters (pH, temperature, salinity and conductivity) were also measured. Samples were analyzed using titration method and with an Atomic Absorption Spectrophotometer (AAS) for organic matter and heavy metals, respectively. Levels of physicochemical parameters were found save for aquatic life according to WHO guidelines. Levels of organic matter were ranged within 8.05±7.32 and 67.74±14.07% with highest contents observed in samples collected in the urban area close to Abidjan city. The analysis of sediment samples showed Pb, Cd, Ni, Mn and Zn levels of mean values 404.75±142.08, 2.85±1.97, 45.63±2.73, 107.46±6.51 and 208.77±81.34 mg kg-1 (dry weight), respectively. Apart from Mn and for samples collected in the rural zone close to Bingerville, sediments were found polluted by Pb, Cd, Ni and Zn with concentrations higher then effects ranged severe levels. Except for Mn (p>0.05), spatial and seasonal variations were significant (p<0.0001) for Pb, Cd, Ni and Zn. Therefore, it is urgent to promote treatment of discharges from industries, urban sewage, port, agricultural, etc., before their input in the Ebrié lagoon as its sediments contamination by heavy metals remains a public health problem.