AbstractThink Aloud (TA), a strategy in which subjects are instructed to verbalize thoughts as they occur while completing an assigned task, was integrated into a study of clinical reasoning during high fidelity patient simulation by baccalaureate nursing students. TA methods in nursing education research with patient simulation have not previously been reported. Concurrent TA (verbalization of thoughts in short-term memory) and retrospective TA (reflective thoughts verbalized during an immediate post-simulation interview) methods facilitated the collection of rich and meaningful data. Students demonstrated distinct patterns in verbalization during concurrent TA, including public and private thoughts, narration of care, and the use of the pause to facilitate clinical reasoning. Retrospective TA data provided rich descriptions of reflection-on-action. TA provides a rich source of data regarding clinical reasoning as experienced by the baccalaureate nursing student during high fidelity patient simulation.