Abstract
The article focuses on comparing the scope of application of Art. 2721 of the Code of Civil Procedure and Art. 192 § 2 of the Code of Criminal Procedure. The Act of 4 July 2019 amending the Code of Civil Procedure and certain other acts introduced a new institution of hearing a witness in the presence of an expert. The study discusses main issues arising from the regulation of Art. 2721 CCP, among others: the scope of the hypothesis of Art. 2721 of the Code of Civil Procedure, the meaning of the optional form of this provision, and implementation of the order regarding participation of an expert in the hearing of a witness under civil proceedings. The article also presents rules of active participation of an expert in case of examination of a party and hearing of a minor.