Empirical evidence has consistently shown that trust facilitates coordination, reduces conflicts and enhances longevity within cooperative relationships. Conditions leading to trust have been considered repeatedly in research papers. Whereas the link between reputation and trust, for example, has been extensively researched, the study of relational competence as a determinant of trust has largely been ignored. Although some academic articles naming the impact of competence on trust exist, the study of the mode of action of relational competence in the trust-developing process is underdeveloped. Therefore, the main purpose of this paper is to analyse the relationship between relational competence and trust. For this reason, a laboratory experiment was conducted. In its conclusion, the paper presents the empirically confirmed strong correlation between relational competence and trust within cooperative relationships by taking into account situational and personal factors.