Three-year school ending with an examination enabling pupils to continue education in basic vocational schools/stage I sectoral vocational schools, general secondary schools or technical secondary schools. The organisation structure of a lower secondary school comprised grades 1-3. Education in a lower secondary school was compulsory.

Lower secondary schools were introduced by the Education System Act in 1999 and liquidated as part of the education system reform of 2016.

• Act of 14 December 2016, the Law on School Education
  Place of publication: (Dz. U. z 2023 r. poz. 900, z późn. zm.)