Changes to procedural legislation of Ukraine in 2017 added a new participant in lawsuit, namely: legal expert. Such an expert can be a person who has an academic degree and is a specialist in the field of law. Legislator did not put forward any other requirements for the new participant in lawsuit, that caused lively discussions, in particular, on the question of whether an expert in the field of law bears legal responsibility in general and what exactly. In view of the above, the purpose of this article is to determine the legal responsibility of forensic expert in the field of law. The methodological basis of the article is separate scientific methods of cognition, in particular: logical-semantic, systemic-functional, comparative-legal, structural-logical (reveals the issue of legal responsibility of an expert in the field of law) and methods of mathematical statistics (for quantitative comparative assessment and qualitative analysis of the obtained results). The article describes the rights and duties of an expert in the field of law, provided for by procedural legislation of Ukraine. Comparison of the procedural status of a forensic expert conclusion in the field of law with the conclusion of forensic research was made. Possible types of offenses by an expert in the field of law are proposed to be systematized into three groups: civil, organizational, and procedural ones. Four types of legal responsibility of forensic expert in the field of law are characterized: disciplinary, civil, administrative and criminal ones.