Aqueous extract of unripe Carica papaya fruit (AEUCPF) was investigated for its anti-ulcer, mucus secretion, anti-acid secretory and pepsin binding effects in rats. Ethanol/HCl and Indomethacin were used to induce ulcers while acid and mucus secretion was measured in ulcerated and treated animals. The animals were divided into five groups for each of the anti-ulcer studies and each group was made up of five animals each. These groups included a control and reference groups administered saline and cimetidine (Kg/Kg b.w), while the remaining three groups were administered with 2.5, 3.5 and 4.5ml/Kg of the decoction of the unripe fruits. The extract, cimetidine and saline were all administered orally twice daily for ten days while necrotizing agents were administered (p.o) once daily from day 8 through day 10. The results showed that higher doses of the extract significantly (p<0.05) reduced the ulcer index from 3.6± 0.24 (control) – to 0.70 ± 0.37 (4.5ml/Kg) in the ethanol induced ulcer. The extract also produced similar effects in the indomethacin induced ulcer and in both cases the gastric acidity was significantly reduced. The extract did not increase mucus secretion but it bind substantially with pepsin. In conclusion this study has shown that AEUCPF has beneficial effects on the normal function of the stomach. It has the capacity to ameliorate gastric ulcer as suggested by local traditional medical practitioners.