The paper aims to present retrospectively the proposals on interpretation of contracts prepared during work of the Codiﬁcation Commission of the Republic of Poland that preceded the enactment of the code of obligations of 1933. It is thereby an opportunity not only to illustrate in outline the process of deﬁning the conclusive version of the code rules on contractual interpretation but also to point out the most signiﬁcant issues determining the selection of appropriate legislative solutions in the ﬁeld of interpretation. Due to the quality of the Polish code of obligations, commonly regarded as a remarkable legislative achievement, such retrospective scrutiny can constitute an important point of reference, especially in view of the contemporary attempts to create an adequate structure of interpretative rules within the ongoing recodiﬁcation process undertaken by the Civil Law Codiﬁcation Commission at the Ministry of Justice that has brought forward a draft of volume I of the new civil code (2008). It has already undergone a thorough revision and currently is set to be published in a modiﬁed version. The development seems particularly important in view of the fact that the general model of interpretation introduced in the code of obligations was – in principle, to some extent – adopted in the civil code now in force. Additionally, the questions examined in the article can be conceptualised in a broader context of the current debate focused on the issues of decodiﬁcation and europeanisation of private law.