•Silicon glass microparticles (SiMPs) induce tolerance to abiotic stresses.•Seed priming mitigated the effects of water restriction in cowpea plants.•Therefore, plants from seeds subjected to SP improve tolerance to water stress. The northeast region of Brazil presents high variations in solar radiation levels and high air temperatures, impairing the growth and production of cowpea, consequently raising the need for technologies to improve the adaptation of cultivated plants. Therefore, this work aimed to promote the tolerance of cowpea (cultivar BRS Itaim) to water deficit induced by polyethylene glycol 6000 through seed conditioning with silicon glass microparticles. The experiment was performed in the field using a completely randomized 6 × 2 factorial scheme design with four replications. Seed priming (SP) consisted of six combinations of water potential (Ψw) and silicon glass microparticles (SiMPs) (T1: Ψw 0 + 0 SiMPs, T2: Ψw 0 + 200 SiMPs, T3: Ψw -0.4 + 0 SiMPs, T4: Ψw -0.4 + 200 SiMPs, T5: Ψw -0.8 + 0 SiMPs, and T6: Ψw -0.8 + 200 SiMPs) and two water replacement levels: plants with water restriction (50 % of water consumption) and without it (100 % of water consumption). Seed priming with silicon glass microparticles and polyethylene glycol 6000 attenuated the deleterious effects of water restriction in cowpea plants through water status homeostasis, osmotic adjustment, and antioxidant mechanism.