Extrusion-cooking of broad beans with a single-screw extruder has been investigated. Attention was focused on process requirements as well as on the nutritional effects of extrusion-cooked broad beans in a chicken feed formulation. The optimal thermal process conditions required for a product of good quality from broad beans are given. Feeding trials with diets containing extrusion-cooked broad beans were carried out and it was found to be possible to replace at least 60% soya in a chicken ration. This work demonstrates that extrusion-cooking of broad beans is an acceptable process for animal feed in respect of protein quality, particularly in countries where Vicia faba are commonly cultivated.