Banana is composed of about 80% carbohydrate mainly as resistant starch. Carbohydrate digestion and released is influenced by many factors, thus different carbohydrates do not have the same effects on blood glucose levels. Glycaemic index ranks equal carbohydrate portions of different foods according to the extent to which they increase glucose levels. We examine the blood glucose response to four different ripe bananas in diabetic and non diabetic Nigerians. 59 subjects were recruited comprising 27 diabetics and 32 non-diabetics. Four species of banana were eaten after weighing to contain the equivalent of 50 g carbohydrate. Blood for glucose were taken at 30, 60, 90 and 120 minutes. The anthropometric data and blood pressure were measured. Diabetics subjects were significantly older 59.7 ± 11.6 vs 45.09 ± 10.36, P<0.01. IAUGC were significantly higher among the diabetes; however, there was no significant differences between the diabetics and non-diabetics glycaemic indices (84.5, 82.9, 83.1, 83.3 vs 80.2, 80.6, 88.2, 76.5). Ripe banana has a high content of simple sugar with a high glycaemic index (>70), thus not very appropriate for diabetic patients achieving good metabolic control.