This pilot study has two areas of focus. It examines how the knowledge and competences of twelve Master's-level systemic counselling trainees are connected, and how well their own assessment of their competence corresponds to external assessment. Methodologically, three instruments were used: first, an instrument to measure their explicit knowledge; second, videos of consultations with simulated clients to measure their competence in practice; third, a self-assessment measure to explore how externally assessed competence corresponds to self-assessment. The results show no indication that knowledge is related to externally assessed competence. Furthermore, their self-assessment did not show any systematic connection to the external assessment. The study concludes that the development of systemic counselling skills is a long-term process of theory acquisition, practise, and reflection. Important reflection processes can be stimulated by self-assessment. However, such assessments are not sufficient to capture the quality and scope of competence.