Critical thinking and the clinical decision-making power of nurses are among the factors to amend the quality of health care. This study aimed to investigate the relationship between clinical decision-making and critical thinking in the quality of nursing care in nurses. This descriptive-analytical study was done with the participation of 226 nurses working in internal surgical departments. Data were collected through California critical thinking skills questionnaires, clinical decision-making, and quality of nursing care and using multi-stage stratified sampling proportional to volume. The findings were analyzed by descriptive and inferential tests (Pearson correlation coefficient, independent t, and one-way analysis of variance) in SPSS software version 23. The average scores of quality of nursing care, clinical decision-making, and critical thinking were 199.43±26.97, 87.72±13.98, and 7.99±3.15, respectively. High nursing care quality and poor critical thinking were reported. Pearson's correlation coefficient did not show a significant relationship between critical thinking score and nursing care quality score (P>0.001), but the results demonstrated a significant relationship between clinical decision-making score and nursing care quality score (P<0.001). The findings of the current study showed that there is a significant relationship between the clinical decision-making score and the nursing care quality score, but no significant relationship was reported between the critical thinking score and the nursing care quality score. In addition, the critical thinking of the participants was reported at a weak level, so the need to train nursing students and nurses to strengthen critical thinking and ultimately improve clinical decision-making power and increase the quality of nursing care is recommended.
