The study examines the penalty of restriction of liberty. The sanction in question occupies a unique position in the Polish catalogue of principal penalties as the so-called intermediate punishment, between a fine and a custodial sentence. Over the last forty years or more the penalty has changed considerably, mainly as a result of difficulties with its application and enforcement as well as its still modest share in the sentencing structure. The aim of the study is to present changes in the substance of the penalty, beginning with the criminal codification of 1969 and ending with the major amendment to the Criminal Code of 1997, which entered into force on 1 July 2015.