Khat (Catha edulis F) belongs to the Celastraceae family and is a dicotyledonous evergreen shrub/tree used for recreation and alleviation of fatigue in several countries of East Africa and South Arabia. Recently, this habit has spread considerably, raising concern in view of medical and socio-economic consequences of khat consumption. Even though khat has several medicinal, social, and economical values, there are numerous reports regarding its gastrointestinal tract (GIT) adverse effects. As the effects of khat chewing on digestive system mentioned in earlier studies were based on clinical observations, the present study was designed to evaluate the GIT activity of the crude khat extract after acute and sub-chronic administration using different rodent models and parameters used for ulcer and motility measurement were quantified. For acute study, animals were randomly assigned into different groups. Negative control received Tween 80 2% in distilled water, whereas positive controls were given ranitidine (pylorus ligation and cysteamine HCl models), misoprostol (indomethacin induced gastric ulcer), and loperamide (castor oil induced diarrhea and enteropooling assay). The other group received different doses of crude khat extract: 100 mg/kg, 200 mg/kg and 300 mg/kg. For sub-chronic study, one group was administered vehicle and served as control, whilst the other three were administered three doses of khat extract (100, 200, and 300 mg/kg) for 45 days.rnAcute khat administration in pylorus ligation model was shown to aggravate ulcer compared to controls in the highest dose used, as evidenced by increased volume of gastric acid secretion (p