<p>This study investigated the extraction of pesticides from agricultural area using a procedure coupled with liquid chromatography tandem mass spectrometry (LC–MS/MS). The water samples were taken from 20 samples of groundwater (Gw) and 5 of surface water (Sw) near Ramsar wetland in Gharb plain in the north of Morocco. Various factors affecting extraction efficiency were assessed during the research. The study revealed the presence of 29% of organochlorines Pesticides (OCP) compounds in explored area. Comparisons between Sw and Gw samples suggested that HCB, Lindan, dieldrin, Aldrin, endosulfan, Heptachlor, DDD, DDE, and DDT were accumulated. Average concentrations were 8 µgL⁻¹ and 10.2 µgL⁻¹ in (Gw) and 11.63 µgL⁻¹ (S5) Oued MDA with an average of 2.52 µgL⁻¹ and 58% of unauthorized organochlorines in both (Gw &amp; Sw). DDT residues and its derivatives in the Gw are non-existent. We were able to detect them with high contents only at the S5 with (DDT = 1.76 μgL⁻¹; DDD = 1.83 μgL⁻¹; DDE = 1.62 μgL⁻¹). The spatial dispersion of diffuse (OCP) has allowed us to notice that the wells and stations that have demonstrated the highest levels are those located in the Southeastern part of the study area, characterized by the intensification of agriculture based mainly on market gardening and citrus fruits.</p>