ABSTRACT This is the first exploratory study that centres on understanding what constitutes effective coaching relationships. Despite existing evidence highlighting the importance of the coaching relationship in achieving successful outcomes, there is limited knowledge on the specific components that make these relationships effective. The purpose of this study is to gain a deeper understanding of the cognitive structures and personal constructs that underpin effective (health) coaching relationships from the perspectives of health coaches, placement officers, and long-term unemployed clients with health restrictions. By employing Personal Construct Psychology and qualitative methods like Repertory Grid Technique, the study seeks to provide deeper insights into how these relationships are construed and what factors contribute to their effectiveness. The analysis identified 27 key themes that contribute to effective coaching relationships, highlighting the importance of relational constructs like trust, empathy, client readiness, and the individualised nature of perceptions, with different factors playing significant roles for different individuals. Repertory Grid Technique and Personal Construct Psychology proved effective in uncovering these cognitive structures. The study’s results offer practical implications for enhancing coaching practices, especially for vulnerable populations.