This article deals with the discovery of an unknown manuscript of the first Polish translation of an ancient Egyptian text. Tadeusz Samuel Smolenski (1884-1909), a student of Gaston Maspero and the first Polish Egyptologist, about 1908 translated into Polish a demotic text Contest for the Breastplate of Inaros directly from the original. The reprint of this manuscript, which unfortunately is preserved incomplete, has been attached.