Sunflower is an important oil seed crop in India. The crop is susceptible to various diseases among which leaf blight caused by Alternaria helianthi is more destructive. The present study aimed at determining antifungal potential of Moringa stenopetala (Baker f.) Cufod (Moringaceae) an indigenous plant to Ethiopia against A. helianthi isolated from sunflower leaves. Antifungal activity was determined by Poisoned food technique. The extract was effective and a dose dependent inhibition of mycelial growth of fungus was observed. At extract concentration 1.5mg/ml and higher, an inhibition of >70% was observed. The plant appears promising and the presence of bioactive principles in the extract might have accounted for the antifungal activity. The plant can be used in the management of leaf blight of sunflower.