This article presents a comparative analysis of the use of specialized knowledge in judicial proceedings, using examples from countries with adversarial (USA, UK), inquisitorial (Germany, France), and hybrid (China) legal systems. The author highlights key issues and examines mechanisms for ensuring the quality of expert opinions: standards, ethical codes, expert lists, and recusal procedures. Particular attention is paid to the trend toward convergence between models combining elements of the adversarial process and judicial instructions. In conclusion, general recommendations are offered for improving the national (Russian) regulatory model for the institution under study and expert practice