We have investigated the effect of a diet containing of 4 % oyster fungus (Pleurotus ostreatus) and 0.1 % cholesterol on glycaemia and hyperlipoproteinaemia in rats with insulin-dependent diabetes (streptozotocin 45 mg/kg). After two months, the rats with diabetes kept on the oyster fungus diet, had a significantly lower basal and postprandial glycaemia, the insulinaemia remained unchanged. The cholesterol concentration was decreased by more than 40 %, the lipoprotein profile was upgraded by the decrease of the cholesterol in both the low density and very low density lipoproteins. The oyster fungus decreased the cholesterol accumulation in the liver and had no significant effects on the levels of serum and liver triacylglycerols.