The plasma glucose and insulin responses were determined in 10 NIDDM female patients following the ingestion of tropical fruit containing 25 g of carbohydrate. The five tropical fruits were pineapple, mango, banana, durian and rambutan. Blood was drawn at 0, 30, 60, 120 and 180 min, respectively. The results showed that the glucose-response curves to mango and banana were significantly less than those to rambutan, durian and pineapple (P less than 0.05). Only the glucose area after mango ingestion was significantly less than the glucose areas of the other fruits (P less than 0.05). The insulin response curve and insulin area after durian ingestion was statistically greater than after ingestion of the others. We concluded that after mango ingestion, the glucose area was lower than it had been after rambutan, durian and pineapple ingestion and the insulin area was lower than that after durian ingestion of equivalent carbohydrate content in type 2 (NIDDM) diabetes.