This study aimed to explore student counsellors' perceptions of ethicality and sources of these perceptions. A sample of 70 Turkish undergraduate student counsellors participated in the study. Data were collected using ethics autobiographies centred on two broad questions. Content analysis showed that participants perceived maintaining confidentiality (81%) as a major criterion of ethicality, followed by respect for individual and cultural differences (67%). The main source of perceptions as cited by the participants was courses taken during their undergraduate training (75.7%). Observation of other counsellors ranked second (32.8%), and text-books ranked third (15.7%). Implications for counsellor education are discussed and recommendations for future research are provided.