An attempt was made to study the antimicrobial activity of saxicolous lichen Roccella montagnei under invitro conditions. The antimicrobial activities of Methanol, Ethanol, Ethyl Acetate and Acetone extracts of Roccella montagnei were assayed against nine pathogenic microorganisms using standard welldiffusion method. The Acetonic extract was found most effective antibacterial whereas the Ethanolic extract was found most effective antifungal against most of the organisms. The maximum inhibition zone was recorded in E.coli with inhibition zone 34 mm. Fungal pathogens showed their inhibition zones in varying levels as 32 mm in Candida albicans and Fusarium oxysporium and 30 mm in Aspergillus niger. The present study reveals that extracts obtained from R. montagnei have potential compounds that can lead to control of human pathogenic microorganisms in the future.