The conditions during pelleting are determinant for diets that contain phytase. Temperature that reaches 80 C or more during the pelleting process of the diet results in a reduction of the digestibility of the P. Results showed that diets that contained phytase after steam pelleting presented the same P digestibility than diet that was phytase-inactivated. Not only the digestibility of P was decreased by pelleting but also the calcium digestibility was also lowered. Consequently, pelleting at high temperature has to be avoided.