The main drug used against Hymenolepis nana is praziquantel (PZQ), which causes side effects and toxicity. In contrast, natural extracts have limited side effects and are safer. Past researches have proved that pumpkin seeds are effective as natural antimicrobial and antiparasitic treatment. The present study investigates a natural alternative and less expensive treatment against H. nana using pumpkin seeds.Healthy female albino mice were divided into four groups: normal control, infected control with H. nana, infected and treated with PZQ, and lastly, the group infected and treated with pumpkin seeds' extract.Pumpkin seeds aqueous extract showed a significant reduction (P < 0.05) in the number and length of H. nana adult worms, number and viability of eggs in comparison to the infected control group and PZQ group. Pumpkin seed aqueous extract is proven to be an effective anthelmintic against H. nana.We recommend pumpkin seed extract as a natural alternative, less expensive and safe therapy for H. nana. This is the first study in Saudi Arabia to investigate the therapeutic effect of pumpkin seeds' extract on H. nana.