AbstractMale rats were chronically fed a diet containing dry powdered seeds ofGarcinia kola, at the level of 10% w/w for 6 weeks. The effect of this diet was investigated on gastrointestinal motility, castor oil induced diarrhea, and pentobarbital sleeping times, as well as organ and body weights at the end of 6 weeks.Garcinia kolacaused marked inhibition of gastrointestinal motility, protected against castor oil induced diarrhea, prolonged pentobarbital sleeping time, and caused marked retardation of growth but did not affect organ weights compared to pair‐fed controls. There is a possibility that the observations may be due to the flavonoids contained inG. kolaseed