Cow pea crop is highly prone to a wide range of pests and diseases, which can cause damage to the crop at all the growth stages. Among the parasitic diseases, viral disease rank first and result in huge grain loss. Among different viral diseases cow pea mosaic disease transmitted by Aphis craccivora Koch is one of the important disease. Management of cow pea mosaic disease so far been undertaken by means of chemical pesticides, irradication of diseased plants and removal of weed host etc. But due to overwhelming evidence of pesticidal risk to humans and other forms of life brings the importance of biological control of plant diseases. Keeping these points in view, the present study was focused on the development of bioformulation of an entomoapathogenic fungus, Metarhizium anisopliae which is a promising biocontrol agent against Cow pea aphid. In this study, two different bioformulations were prepared and six oils and three adjuvants at different concentrations were tested. Efficacy of both these formulations were tested against A. craccivora in pot as well as in field condition. This work will be helpful for scientists, research scholars, students working in biological control.