A field experiment was conducted during kharif 2008 at Junagadh on effect of bio fertilizer and fertility levels on yield, protein content and nutrient uptake of cowpea. Sixteen treatments comprising of four levels of bio fertilizer viz., without inoculation, with PSB inoculation, liquid PSB inoculation and Rhizobium inoculation and four fertility levels viz., 0, 50, 75 and 100 % RDF were tried in factorial randomized block design with four replications. The result of the experiment indicated that significantly the highest grain and stover yield of 1441 and 1716 kg/ha respectively, was recorded in seed inoculation by Rhizobium over rest of the treatments. The increased in RDF significantly increased seed and stover yield. Inoculated with Rhizobium significantly increased protein and N, P content as well as uptake of N and P by grain and stover. The 100 % RDF recorded the highest protein content as well as content and uptake of N and P by grain and stover but was par with 75 % RDF. Significant improvement in available N and P status in soil was also reported due to Rhizobium inoculation.