In India, the state of West Bengal is characterized by amalgamation of various altitudinal, climatic and edaphic factors. As a result, it can host and flourish diverse groups of organisms. However, data regarding the biodiversity of the fungi in the state of West Bengal is inadequate. Therefore, an extensive mycological survey was conducted by the authors in this state in 2022, and during this survey, some mature basidiocarps of a fungus along with some egg-like immature ones were found growing on the forest floor of the village of Moukura in the district of Bankura (West Bengal, India). The climate of the region was warm and humid. Some of the egg-like structures opened irregularly from their apex to form a basidiocarp consisting of a cap or receptacle with pentagonal pores, stipe or stalk and volva. The basidiocarps were identified based on macromorphological and micromorphological features as of Lysurus periphragmoides (Klotzsch) Dring. Some mature basidiocarps were found to be diseased. Symptoms of the disease were found as scattered black spots on the stipe with cottony green areas around some of these spots. The disease was thus identified as “green mold disease” and it constitutes the only report of any disease of a species of Lysurus Fr. When diseased tissues of basidiocarps were examined microscopically, the hyphae of the pathogen were found penetrated within the hyphae of the host. The pathogen was isolated on potato dextrose agar (PDA) medium from diseased basidiocarps of Lysurus periphragmoides (Klotzsch) Dring growing in the wild and its identification was confirmed as Trichoderma pleuroticola Yu & Park based on its cultural characteristics, micromorphological features and DNA sequencing data. In the present paper, Trichoderma pleuroticola Yu & Park has been reported for the first time from India which acted as a mycoparasite causing green mold disease on Lysurus periphragmoides.