Cowpea (Vigna unguiculata (L.) Walp), a legume with high nutritional value, is widely consumed by West African populations. In Burkina Faso, its yields in rural areas are relatively low due in particular to the perpetuation of old farming methods and especially the low level of soil fertility. The study aims to evaluate the effect of three types of organic manure on the agro-morphological parameters of cowpea. An experimental design in completely randomized blocks with four treatments (T0 = control without organic manure; T1 = cattle dung; T2 = poultry droppings; T3 = sheep dung) and four repetitions was used. The results showed that the weight of 100 seeds did not vary under the influence of the types of fertilizers compared to the control treatment. However, the total number of seeds produced per plant was significantly higher (p˂0.001) under the T2 treatment (102±3 seeds). As for the T1 and T3 treatments, they led to the lowest values of this parameter (respectively 69±4 and 65±4 seeds).