[en] The crystallographic texture developed during the manufacturing of ZRY-4 cladding tubes has been extensively studied by Tenckhoff and Rittenhouse. The amount of activity of pyramidal slip in cold rolling of ZRY-4 is still a controversial point. For example, in a work by Pochettino et al. only the aforementioned twin systems and prismatic slip were taken into account to perform a simulation of the final (0002) pole figure, resulting from a cold rolling of a plate up to 50% thickness reduction. From a technological point of view, the knowledge about the amount of activity of pyramidal slip is of major importance, because, if it were large enough it would allow larger strain per step in order to reduce the number of intermediate annealings. The purpose of this work was to use the Orientation Distribution Function (ODF) to study in details the orientation changes of the crystallites, in order to reveal the operation of pyramidal slip