Resumo. This work aimed to evaluate the interaction between P-solubilizing microorganisms and organomineral fertilizers in order to increase the cowpea nutrition and yield under field conditions. One field trial was carried out in a randomized complete block design arranged in subdivided plots (7 x 3) with four replicates. The organominerals (poultry litter, swine manure, filter cake and soot from chimneys) as well as triple superphosphate (TSP) with and without sulfur and the control treatment (no fertilizer addition), were considered the primary factor. The secondary factor was constituted by inoculation of Bradyrhizobium sp. SEMIA 6462 (Simbiose Nod Caupi®), one P-solubilizing bacteria (MBSF2) as well as no inoculation treatment. The MBSF2 inoculation combined to the soot organomineral increased the shoot length at 50 DAE. The stem diameter, shoot and root dry matter at 50 DAE were increased by Bradyrhizobium spp. inoculation and poultry litter. Also, the stem diameter was increased using filter cake organomineral and both inoculants. The nodules number was also increased by use of that organomineral combined to Bradyrhizobium spp.