The aim of present study was to examine the effect of arbuscular mycorrhizal fungi (AMF) on the growth, lipid peroxidation, antioxidant enzyme activity and some key physio-biochemical attributes in cowpea (Vigna unguiculata [L.] Walp.) subjected to salt stress. Salt stress (200 mM NaCl) reduced growth, biomass, relative water content and chlorophyll pigment content in cowpea leaves. AMF ameliorated the negative impact of salinity on the growth parameters studied. The activity of antioxidant enzymes such as superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), peroxidase (POD) and glutathione reductase (GR) enhanced under salt stress and AMF inoculation further enhanced their activity, thus strengthening the plant’s defense system. Proline content increased in salt stressed plants as well as AMF-inoculated plants providing efficient protection against salt stress. Besides this AMF also increased uptake of mineral elements which have direct impact on the osmoregulation of the plants. The present study shows that AMF possesses the potential to enhance salt tolerance of cowpea.