A total of 560 day‐old commercial broiler chicks were used in two experiments conducted to investigate the biotin requirement of broilers fed sunflower seed meal (SSM) based diets. Two basal biotin‐deficient diets based on dehulled (Experiment 1) and non‐dehulled (Experiment 2) SSM were each supplemented with graded levels of biotin so that the rations had 40, 80, 120, 160, 200, 240 and 280 mcg/kg feed. Therefore a total of 14 treatments were tested. Each treatment was given to duplicate floor pens with 20 chicks each for a period of 28 days.