The author presented a brief history of the Prussian middle school in Chojnice - the Royal Catholic Grammar School. The institution was involved in didactic and educational activities in 1815-1919. From among 1,355 of its graduates many continued their education by studying theology. Every fourth alumnus of the grammar school became a Catholic priest. Medical and law studies were also popular, and later technical studies as well. The Chojnice school educated young people of three denominations - Catholics, Protestants and Jews. Describing the history of the school and its alumnae, the author mentioned 27 pupils coming from Bydgoszcz and Bydgoszcz County