Potato is one of the most vegetable crops consumed in the world. Many cultivars of potato infested by Black scurf disease (Rhizoctonia solani) and affect the quantity and quality of the yield. An experiment was conducted to study the effect of clove extract for controlling R. solani. Six isolates were obtained from infected potato plants from different potato growing areas. The results obtained from the pathogenicity test cleared that lady rosetta potato cultivar was the most susceptible cultivar to R. solani as affect number of plants. While the most resistant cultivar to R. solani during the Pathogenicity test was cara potato cultivar as affected by R. solani as affect the mean number of plants. On the other hand, among all six R. solani isolates tested during the pathogenicity study Rs4 was the most pathogenic isolate on potato plants while the lowest pathogenic isolate was Rs6 on the tested potato cultivars as affecting the number of plants/ pots. The results for the effect of clove extract (alcoholic and water extract) showed that alcoholic extract was very effective to inhibit the growth of all six R. solani isolates as the pathogen was totally inhibited while clove water extract was less effective for inhibiting the growth of the pathogen comparing with control treatment.