The study assesses farmers’ perceptions and willingness to pay for a biopesticide developed from Metarhizium anisopliae a fungi. A sample of 400 conventional and organic cotton producers was randomly selected in cotton producing zones in Benin and interviewed for their perceptions on the efficacy of the biopesticide and the likely prices they are willing to pay for the product to control a major pest like Helicoverpa armigera or cotton bollworm causing substantial crop losses. An econometric model (Logit) is used to identify factors highly likely to affect farmer’s willingness to purchase the product. The results show that Helicoverpa armigera or cotton bollworm is perceived by farmers as the most severe pest with losses reaching up to 100%. Farmers attribute the current pest intensity to a number of factors including ineffectiveness of chemical pesticides, delay in access to input mainly fertilizers and the development of refuge host plants for cotton pests. The results also show that most cotton producers and their households members are exposed to chemical insecticides without adequate protection devices during the pest control sprays. Both organic and conventional cotton producers have expressed a significant interest in the use of Metarhizium to control Helicoverpa on cotton. Both types of farmers willing to pay more for any pest control product that would improve cotton product quality for higher cotton price. Three variables influencing farmers’ willing to pay for biopesticides from Metarhizium were efficacy, agro-ecological zone and broad spectrum.