In 1947 the first scientific work on Boleslaw Walewski was written, entitled "Biography and Religious Work of Boleslaw Walewski". New sources and information about Walewski and his work made it necessary to thoroughly revise the biography and complete the study. The aim of this dissertation is to give an overview of the biography and religious works of the above-mentioned composer. After an overview of his biography, his musical and compositional activities in general are discussed. The author has succeeded in establishing dates and correcting repeated inaccuracies, as well as taking a critical look at Walewski's religious works.