Influence of microwave and heat treatment in a household oven on the nutritive value of full-fat soy beans as determined by an urease index, the FDNB test for available lysine and a broiler growth test. The microwave treatment of soy-bean samples was studied on the basis of duration of treatment and moisture content as variables. This was compared to heat treatment in an ordinary household oven where duration of treatment, moisture content of soy-bean samples and oven temperature were sources of variation. Microwave treatment was effective after 11 min at a moisture content of 15,3% and after 8 min at a moisture content of 22,0% as judged by the urease index method. At 22,0% moisture content available lysine according to the FDNB test, reached maximum values after 6-8 min of microwave treatment, whereafter availability declined sharply. Results with the ordinary household oven were more variable, suggesting different optimum treatment conditions with different combinations of the variables studied. The best performance of broilers in terms of mass gain and feed conversion ratio was realized with soy beans treated for 8-14 min in the microwave oven. These samples contained 22,0% moisture and the soy beans were included at a level of 30% in the broiler diets. The best results for treatment in the ordinary household oven were obtained after 22,5 – 25 min treatment at 225 °C oven temperature and soy-bean moisture content of 15,3%. The pattern of pH change in the urease index corresponded satisfactorily with the pattern of broiler performance which suggests that the urease index method could be valuable as a routine test in commercial operations. It was further concluded that microwave treatment is a more reliable and convenient method than dry-heat treatment in a household-type oven.