OBJECTIVES: To provide insights into the validity and acceptability of the Discrete Choice Experiment (DCE) and profile case Best Worst Scaling (BWS) methods for eliciting preferences for health care. METHODS: A convenience sample (N=24) undertook a traditional DCE and a BWS choice task as part of a wider survey on Health Technology Assessment decision criteria. A ‘think aloud’ protocol was applied, whereby participants verbalized their thinking while making choices. Internal validity and acceptability were assessed through a thematic analysis of the decision-making process emerging from the qualitative data and a repeated choice task. RESULTS: The think aloud data demonstrated clear evidence of ‘trading’ between multiple attribute/levels for the DCE, and to a lesser extent for the BWS task. For the BWS task, some participants found choosing the worst attribute/level conceptually challenging.  A desire to provide a complete ranking from best to worst was observed. The majority (18,75%) of participants indicated a preference for DCE, as they felt this enabled comparison of alternative full profiles. Of those preferring BWS (3,50%) indicated  the primary reason was related to the ability of BWS to remove the potential requirement to choose an undesirable characteristic that was part of a ‘package’, (1,17%) perceived the BWS to be less ethically conflicting, and (2,33%) perceived BWS to be less  burdensome. More participants were consistent for the DCE (22,92%) than BWS (10,42%) repeated task (p=0.002); for BWS, lack of consistency was not observed to be associated with the choice (best or worst). CONCLUSIONS: This novel study supports the validity and acceptability of DCE methods for assessing preferences. The findings relating to the application of BWS profile methods are less definitive than for the traditional choice task. However, important avenues for future research to further clarify the comparative merits of DCE and BWS preference elicitation methods are identified.