Although there are many effective drugs available to treat intestinal worms, the fact remains that they remain out of reach to a majority of the population in many areas of the world. On the other hand, traditional plant-based remedies continue to be an important therapeutic aid for treating worm infections throughout the world, especially in the developing nations. Solanum myriacanthum Dunal is a perennial shrub that is used in the folk medicine of Tangkhul Naga tribe of India for treating intestinal worms. This study evaluates the anthelmintic activity of its ripe fruit extract using experimental Hymenolepis diminuta (a zoonotic tapeworm) infections in albino rats. The efficacy of extract was adjudged by monitoring the eggs per gram (EPG) count of parasite as well as by the direct count of surviving worms in the intestine following treatment with methanol fruit extract of this plant to different groups of rats harbouring H. diminuta infections. The plant extract showed a dose-dependent reduction of both EPG as well as worm counts for all the developmental stages of H. diminuta in rats. However, the effects of the extract were more apparent on the adult stages than larval or immature stages of the parasite. Against the adult stage, a single oral dose of 800 mg/kg of extract, given for 3 days, showed 60.49% reduction in the EPG counts and 56.60% reduction in the worm counts in the extract-treated group as compared to untreated control. In comparison, the reference drug praziquantel (5 mg/kg) showed 51.81% and 70.00% reduction in the EPG and worm counts, respectively. The LD50 (oral) of the extract was determined to be 3,093.24 mg/kg in rats, and no significant changes were observed in the values of serum glutamate oxalate transaminase, serum glutamate pyruvate transaminase, cholesterol and total protein between the extract-treated and control groups of animals. These findings indicate that ripe fruits of S. myriacanthum possess significant anthelmintic property, without any adverse effects to the experimental animals. This may provide a scientific rationale for the traditional use of this plant against intestinal worms.