The Abidjan lagoon pollution evaluation via the physicochemical and biochemical characteristics of effluents pouring in it, in order to take decision concerning the installation of a treatment station was reported. All samples of effluents studied contain high quantity of organic and mineral pollutants except for samples from a hospital (effluent II). However, the analysis of the ratios COD/BOD of the different effluents showed that the corresponding wastewaters have a domestic character and are therefore easily biodegradable. @JASEM