In November 1918, after one hundred and twenty three years of subjection to the rule of invaders and non-existence as a sovereign state, Poland regained its independence. Within the territory of the Republic of Poland, as far as judicial law is concerned, there existed five different legal systems as a remainder of the period of the Partitions – the Austrian, Prussian, Russian, French (Books II and III of the Napoleon Code) and Hungarian (in the regions of Spis and the Oravas). The newly reborn Polish State faced the extremely important challenge of unification of law, related with its codification. For that objective, on the 3rd of June, 1919, the Polish Parliament (the Sejm) created a Codification Committee whose task was to propose legislation in the fields of civil and penal codes for the whole territory of Poland. The object of research interest presented herein was to recapitulate and popularise the knowledge on the creation of the Polish system of judicial law and about its authors, and on the results of the legislation works undertaken during the period of existence of the Second Republic of Poland. The time-span covered in this paper is the period of 1919–1939, and the paper is composed of an Introduction and the main body of the text that includes the following Chapters: The State of the Law System; The Necessity of Codification; The Codification Committee; The Results of Codification Works. The Conclusion of the paper presents an analysis and a synthetic evaluation of the subject matter.