The effect of added gastric lipases on the ripening and flavour development in Ras cheese was studied. Ras cheese was made from pasteurized milk with the addition of Italase, Capalase K or Capalase KL at the rate of 12 g/100 kg milk before renneting and analysed at different intervals for fat, moisture, salt, pH, soluble tyrosine and tryptophan and Shilovich ripening index. The organoleptic properties of the cheeses were also assessed. The addition of lipases was found to accelerate the development of flavour, particularly when Capalase K was used. These lipases had no effect on the gross composition of cheese during ripening.