Abstract: Anastomosis groupings and virulence of 229 Rhizoctonia solani isolates, obtained from bean plants and soils in Samsun province, were determined. About 59 % of the isolates belonged to anastomosis group AG 4, 31 % to AG 2-2 and the remaining 10 % to AG 5. All the isolates selected for the pathogenicity test were found to be virulent at varying degrees to eight plants from different families. Isolate HAF 1-3 belonging to AG 4 were found to be the most virulent isolate. Sugarbeet was the most susceptible plant species while corn and leek seemed to be rather resistant. The virulence of the isolates on different bean cultivars varied. AG 4 and AG 2-2 group isolates caused severe symptoms of root rot on all cultivars. AG 5 isolate was highly to moderately virulent regarding the susceptibility of the bean cultivars. Horoz was found to be the most susceptible bean cultivar.