ContextCost-conscious care is critical for healthcare sustainability but evidence suggests that most doctors do not consider cost in their clinical decision making. A critical step in changing this is understanding the barriers to encouraging behaviours and attitudes related to cost-conscious care. We therefore conducted a qualitative study to address the research question: what factors influence consideration of cost in emergency medicine (ED) clinical decision making?MethodsThis was a qualitative focus group study using patient vignettes to explore attitudes towards cost-conscious clinical decision making. Participants were Year 4 and Year 5 medical students from Singapore, a country with a fee-for-service healthcare system. After a data-driven initial data analysis, and to make sense of a multitude of factors impacting on cost conscious care, we selected Fishbein’s integrative model of behavioural prediction to underpin secondary data analysis.ResultsVia four focus groups with 21 participants, we identified five main themes relevant to the integrative model of behavioural prediction. These were: attitudes towards considering cost when managing a patient (e.g., “better safe than sorry”); normative beliefs (e.g., doing what others do, perceptions of patient wishes); efficacy beliefs (e.g., no authority to take decisions or challenge); skills and knowledge (e.g., little knowledge of costs), and environmental constraints (e.g., the nature of the healthcare system).DiscussionMedical students do not consider cost in their clinical decision making due to numerous factors, of which lack of knowledge of costs is but one. While some of the factors identified reflect those found in previous studies with residents and fully-trained staff, and in other contexts, theory driven analysis added value in that it facilitated a richer exploration of why students do not consider cost in clinical decision making. Our findings provide insight to inform how best to engage and empower educators and learners in teaching and learning about cost-conscious care.Supplementary InformationThe online version contains supplementary material available at 10.1186/s12909-023-04349-3.