Objective. Ensuring uniformity of forensic medical expertise in cases related to the improper provision of medical care; reducing the load on public forensic expert institutions by reducing the number of repeated examinations; raising the authority of forensic medical expertise service via introducing a unified approach to assessing the presence and nature of cause and effect relationship. Material and methods. The authors provide expert and court practice examples to show fundamental differences in forensic medical assessment of causal relations of improper provision of medical care with an adverse outcome. A focus is given to the court’s assessment of expert opinions in a criminal process. Results. The authors emphasize the imperfection and inconsistency of methods for assessing the cause-and-effect relationship used by expert commissions. This leads to controversial expert opinions on the same facts in the case and results in administering repeated examinations and prolonging the duration of the preliminary investigation. Conclusion. There is an objectively determined need to develop exact and clearly defined criteria for causal relations of improper provision of medical care with an adverse outcome. © 2024, Media Sphera Publishing Group. All rights reserved.