This study aimed to evaluate the inhibitory and lethal effects of root extracts of the Wild Rue plant (Peganum harmala L.) against the pathogenic fungus Rhizoctonia solani under laboratory conditions. Two types of extracts (aqueous and alcoholic) were used at concentrations of (5%, 10%, 15%, and 20%). The results indicated that the effectiveness increased proportionally with the concentration. The inhibition rate of the aqueous extract reached 64.8% at a concentration of 20%, while the alcoholic extract was significantly superior, reaching 84% at the same concentration. Statistical analysis confirmed highly significant differences between concentrations (P < 0.001) as determined by one-way ANOVA, while two-way ANOVA showed extract type, concentration, and their interaction were significant factors, explaining approximately 85% of the total variance. The study concluded that the alcoholic extract is more effective than the aqueous one in inhibiting R. solani, making it a promising option for fungal control as a safe alternative to chemical pesticides.