This study evaluated the effects of a critical reflection program utilizing the Lasater Clinical Judgment Rubric (LCJR) reflective questions based on the Clinical Judgment Model (CJM) on newly graduated nurses' clinical judgment skills. A total of 153 newly graduated nurses scheduled for on-site training in a ward nursing unit were divided into a control group (receiving only the usual on-site training with preceptorship) and an experimental group (receiving the developed program with the same on-site training with preceptorship as the control group). Data were collected at baseline, 6 weeks, and 3 months after the intervention. A comparison of the scores of the two groups at each measurement time point revealed that the experimental group showed significantly higher scores than the control group in clinical judgment (z = 3.25, p = 0.003) and stage of noticing (z = 2.78, p = 0.015) at 6 weeks postintervention. Clinical reasoning competence (experimental χ