A root rot disease of wild sunflower species (Helianthus tuberosus L) was observed during May, 1992 at National Agricultural Research Centre (NARC), Islamabad. Infected roots showed light brown discoloration, covered with white, fan shaped mycelium with small, round, tan to brown coloured sclerotia of mustard seed size (0.5-2 mm) on the roots and in adjacent soil. Disease incidence ranging from 30-40 % was recorded. On the basis of disease symptoms and cultural characteristics, the causal agent was identified as Sclerotium rolfsii Sacc. Thus, Helianthus tuberosus appears as a new host of this pathogen in Pakistan.