The objective of this study was to evaluate the efficacy of aqueous extract of ricin oil leaves on pests of two cowpea varieties in the field (Diamond and Mujilanga «H36» varieties) and to determine the best dose that promotes good yield. For the experiment, a completely randomized split plot design with four blocks and five treatments was set up, including the control (T0), Zalang 50EC (chemical insecticide) at 1 L/m2 (T1), ricin leaf aqueous extract at 1.125 L/ m2 (T2), ricin leaf aqueous extract at 1.375 L/ m2 (T3) and ricin leaf aqueous extract at 1.625 L/ m2 (T4). The results obtained; with regard to the production variables, the best treatments that induced a high yield were T1 with 1.20T/ha and T3 with 0.935T/ha for the diamond variety (V1) and T1 with 1.22T/ha and T3 with 0.915T/ha for the Mujilanga variety (V2). As for the phytosanitary variables, the insect pests identified before and after the first application of phytosanitary products (organic and synthetic) were Ootheca mutabilis, Thrips megalothrips, Mylabri ssp, Muracate vitrata and pod bugs. After the second application, Aneplocnemis curvipes appeared while Thrips megalothrips and Mylabri ssp were no longer identified. The number of these insect pests decreased significantly after the application of plant protection products, except for the control treatment (T0) in which the number of insect pests increased with the cowpea crop cycle.