Background: Leaves of Caesalpinia bonducella (L.) Roxb., have been traditionally used as herbal remedy against intestinal helminths helminth infections in traditional medicine of India. Aim: This study was undertaken to evaluate the potential in vitro and in vivo anthelmintic effects of C. bonducella leaf extract against Syphacia obvelata (Nematoda) and Hymenolepis diminuta (Cestoda). Materials and Methods: The in vitro anthelmintic activity of the extract was investigated on adult Syphacia obvelata (Nematoda) and Hymenolepis diminuta (Cestoda) worms in terms of physical motility and mortality of parasites. The in vivo study was performed in H. diminuta-rat model and S. obvelata-mice model, by monitoring the egg per gram (EPG) of faeces count and worm count of animals following the treatment with different doses of plant extract. Results: The study recorded significant and dose-dependent anthelmintic effects of extract on both the parasites. In the in vitro study, 30 mg/ml concentration of extract caused mortality of H. diminuta in 2.5±0.2 h and S. obvelata in 3.57± 0.16 h. In the in vivo study, the extract showed a comparatively better efficacy on S. obvelata, where its 800 mg/kg dose revealed 93% reduction of worm load in mice, as compared to 85% reduction of H. diminuta worms in load. Conclusions: The findings suggest that leaf extract of C. bonducella possesses significant anthelmintic effects, and supports its use as an anthelmintic in traditional medicine. This appears to be the first report of in vivo anthelmintic activity of Caesalpinia bonducella against these parasites [J Complement Med Res 2016; 5(4.000): 427-433]