Background: Critical thinking is an essential attribute of a nurse. Nursing education which incorporates simulation and debriefing learning activities has an important role to ensure key components of safety and clinical effectiveness are present before nursing students graduate. Aims and methods: To examine, using Quality and Safety Education for Nurses (QSEN) based rubrics, the relationship between simulation debriefing and critical thinking in nursing students enrolled in an accelerated second degree baccalaureate program. Results: Univariate Spearman Rho regression showed a significant direct relationship between critical thinking and all five components of debriefing (allowing reflection on student’s clinical judgement and approach to patient care; feedback received supportive and constructive; feedback helpful to learning; adequate time given to reflect and discuss clinical performance; and helping understand the rational for the actions and responses to performances). Logistic multivariate regression revealed that only three out of the five debriefing components predicted developing stronger critical thinking skills: allowing reflection on student’s clinical judgement and approach to patient care (χ 2 = 34.249, p = .011), adequate time given to reflect and discuss clinical performance (χ 2 = .068, p = .030), and helping understand the rational for the actions and responses to performances (χ 2 = 119.365, p = .001). Conclusions: Debriefing is an important aspect of simulation which helps enhance critical thinking skills in nursing students and thus should be appropriately addressed in education and research.