The anti-ulcer activities of aqueous extract of unripe plantain peels (Musa paradisiaca) were evaluated in this study using standard methods. Twentyfivemalewistar (albino) rats were starved and randomized into five groups designated A,B,C,D and E. Groups A (positive control) and B (negative control) animalswere administered with 2ml/kg and 50mg/kg bodyweight of distilled water and reference drug (cimetidine) respectivelywhile 50mg/ kg, 100mg/kg and 200mg/kg bodyweight of the extractwere administered intraperitoneally to animals in groups C, D and E respectively and after four hours, 90% ethanol(1mg/kg body weight) was administered to the rats in all the groups. Then the animals were anaesthetized after two hours using chloroform, and their stomachs were dissected and hematological studies were carried out. The result showed that the ulcer index activity for groupA(positive control) had a significant change (P<0.05) compared to groups B (negative control), C, D. and E respectively. The percentage cytoprotective effects were very high in group E, but significantly reduced in groupA(positive control) (P<0.05). These results therefore confirmthat the aqueous extract of unripe plantain peels (Musa paradisiaca) has antiulcer effects and as such could be useful in ethno-medicine for ulcer treatment.