Cassia obtusifolia L. is commonly used as medicinal foods to treat gastrointestinal disease in many countries. This study evaluated the anti-constipation effects of ethanolic extract of Cassia obtusifolia L. in rats with loperamide-induced constipation. Diffferent concentrations of ethanolic extract of Cassia obtusifolia L. (0, 10, 250, and 500 mg/kg) was administered to rat orally once daily for 3 weeks following loperamide treatment. Six-week-old Sprague-Dawley rats (N=25) were randomly divided into five groups: normal control and experimental groups and injected loperamide intraperitoneally to induce constipation in the latter four experimental groups. Following the induction of loperamide-induced constipation, a marked decrease was observed in the fecal weight and water content discharged for over 1 week and intestinal transit time while an increase was observed in the number of fecal pellets remaining in the colonic lumen as compared with the normal control group. These conditions were significantly alleviated following the administration of the two doses (250 and 500 mg/kg) of ethanolic extract of Cassia obtusifolia L. when compared to the loperamide-treated (constipation control) group. More specifically, the number of fecal pellets in the colon was 3, 5, 4, 2.8, and 1.2 in the five groups, respectively and the corresponding GIT ratio was 70.77, 56.59, 58.67, 66.81, and 72.10%, respectively. The fecal water content, transit distance, and GIT ratio in the high-dose treatment group were significantly higher than that in the medium-dose treatment group, but a significant decrease in the number of fecal pellets in the colon. In conclusion, the Cassia obtusifolia L. extract is suggested to have beneficial effects as a therapeutic and preventive strategy to alleviate constipation and to relieve the symptoms of constipation such as pain, flatulence, distention, bloating, and unpleasant taste.