Chilli (containing the active ingredient capsaicin) forms an important flavouring agent in the preparation of meals in the tropics. Previous studies have shown that capsaicin in high doses causes gross structural and functional changes in the gut. The present study investigates the effect of pure capsaicin on the absorption of glucose, water and alanine by the small intestine of the rat. Perfusion studies were carried out using a 10 cm jejunal segment. Absorption rates of glucose, water and alanine from a control solution containing the nutrient and from a test solution containing added capsaicin were compared. Recovery of absorptive function of the intestinal mucosa after exposure to capsaicin was also studied. Absorption of water, glucose and alanine was found to be significantly reduced in the presence of capsaicin. Recovery of absorptive function occurred when capsaicin was withdrawn from the perfusate. It was concluded that capsaicin adversely affected absorption of nutrients from the rat small intestine; this effect was reversible at least in the case of some nutrients.