The presented text is an edition of the schematism of the Samogitian diocese prepared for 1831. The information gathered in it allows one to learn about the state of the Catholic Church, especially its administrative structure in Samogitia before the outbreak of the November Uprising. The collapse of the independence uprising directed against the Russian invaders initiated repressions that significantly limited the Church’s pastoral activities. The material describing the Samogitian diocese at the end of 1830 was divided into three articles. The first includes a critical edition of the schema of the Samogitian diocese published for 1831, along with a discussion of the formation of the rules for preparing Samogitian schemas for printing from the first found catalog of 1787 until the outbreak of the November Uprising. The second will present the administrative structure of the Samogitian diocese and the history of the temples then existing in the Samogitian diocese. The last – third – article will publish data on the diocesan clergy working in the Samogitian diocese on the eve of the outbreak of the uprising, as well as biographies of the priests mentioned in the schema.