The aim of the present study is to assess the contamination degree of Oualidia lagoon surface water by organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) through the monitoring of 13 compounds from the Stockholm Convention black list. Liquid-liquid extractions followed by gas chromatographic technique with electron capture detector (GC-ECD) are used for the analysis of these compounds. The assessment results reveal the presence of organochlorines in the lagoon with enrichment from downstream to upstream. PCBs are most abundant than OCPs with averages of 0.008 and 0.004 μg/L, respectively. p,p’ DDT is the most dominant metabolite reaching 0.023 μg/L. Among the 6 targeted PCBs, the CB180 congener is the most abundant with a concentration of 0.025 μg/L. Interactions between physico-chemical parameters of Oualidia lagoon water and the targeted compounds have been studied. Principal component analysis (PCA) results indicated that some positive correlations are observed.