Given the nature of the discipline, it might be assumed that clinical psychology is an ethical profession, within which effective ethical decision-making is integral. How then, does this ethical decision-making occur? This paper describes a systematic review of empirical research addressing this question. The paucity of evidence related to this question meant that the scope was broadened to include other professions who deliver talking therapies. This review could support reflective practice about what may be taken into account when making ethical (...) decisions and highlight areas for future research. Using academic search databases, original research articles were identified from peer-reviewed journals. Articles using qualitative, quantitative and mixed methods were included. Two theoretical models of aspects of ethical decision-making were identified. Areas of agreement and debate are described in relation to factors linked to the professional, which impacted ethical decision-making. Factors relating to ethical dilemmas, which impacted ethical decision-making, are discussed. Articles were appraised by two independent raters, using quality assessment criteria, which suggested areas of methodological strengths and weaknesses. Comparison and synthesis of results revealed that the research did not generally pertain to current clinical practice of talking therapies or the particular socio-political context of the UK healthcare system. There was limited research into ethical decision-making amongst specific professions, including clinical psychology. Generalisability was limited due to methodological issues, indicating avenues for future research. (shrink)