Clinicians who teach are essential for the health workforce but require faculty development to improve their educational skills. Curricula for faculty development programs are often based on expert frameworks without consideration of the learning priorities as defined by clinical supervisors themselves. We sought to inform these curricula by highlighting clinical supervisors own requirements through answering the research question: what do clinical supervisors identify as relative strengths and areas for improvement in their teaching practice? This mixed methods study employed a modified version of the Maastricht Clinical Teaching Questionnaire (mMCTQ) which included free-text reflections. Descriptive statistics were calculated and content analysis was conducted on textual comments. 481 (49%) of 978 clinical supervisors submitted their mMCTQs and associated reflections for the research study. Clinical supervisors self-identified relatively strong capability with interpersonal skills or attributes and indicated least capability with assisting learners to explore strengths, weaknesses and learning goals. The qualitative category 'establishing relationships' was the most reported strength with 224 responses. The qualitative category 'feedback' was the most reported area for improvement, with 151 responses. Key areas for curricular focus include: improving feedback practices; stimulating reflective and agentic learning; and managing the logistics of a clinical education environment. Clinical supervisors' self-identified needs provide a foundation for designing engaging and relevant faculty development programs.