
The purpose of this article is to examine the institution of an expert in the Polish Code of Civil Procedure of 1930, in particular the significance of expert evidence in the form of an expert opinion. The expert opinion was one of the means of evidence mentioned in the chapter on evidence of the Code of Civil Procedure. During the trial, the court assessed the credibility of the expert opinion on the basis of its conviction. However, since the facts on which the experts give their opinion are excluded from the court's assessment, the court had to rely on such evidence prepared by experts. According to the doctrine, the expert's opinion had the same significance as the court's verdict, and it often settled the case.