Significance and Impact of the Study: An unusual white root rot disease was witnessed on the groundnut plant (Arachis hypogaea L.), and based on the morphological and molecular studies, the pathogenic fungus was identified as Marasmius palmivorus (Sharples). This is the first report of this species causing white root rot in the groundnut plant. Thus, this study provides an information about emerging new fungal disease in the groundnut plant, which will further help for early management and monitoring of the disease in the cultivars.