This article addresses the issue of a patient’s ability to consent to treatment. This issue is analyzed in the context of the assessment of legal capacity under the Civil Code and seeks to highlight the fact that the strict application of the rules on legal capacity may be unduly restrictive for some people in the context of giving informed consent. Therefore, the article seeks to offer a more appropriate solution that would better protect the interests of the subjects concerned. In this context are analyzed theoretical concepts of competence in detail to determine a person’s capacity to act, i.e. to assess their competence. Based on a brief comparison, the article shows that in some states, the issue of a patient’s ability to consent (competence) is considered separately from their legal capacity to act and is more contextually defined.