Metacognitive skills are an important component of lifelong learning that can help individuals become more effective self-directed learners, critical thinker, and decision-makers and can be developed through deliberate practice and instruction. The aim of this study was to assess the effect of metacognitive program on Nursing Students critical thinking. Methodology: An experimental design was used to conduct the present study, at the faculty of nursing, Zagazig University. The sample included 70 nursing students in the fourth academic year divided into two equal groups; study and control group. Two tools were used for data collection; 1) Metacognitive Awareness Inventory 2) California Critical Thinking Skills Test. Results: After the program implementation the highest nursing students in the study group had a significantly higher level of metacognition compared to those in the control group (80% & 11.42% respectively). Before the program implementation, the highest percentage of nursing students in both the study and control groups had low level of critical thinking (91.7% & 90.4% respectively). However, after the program was implemented, more than half of the nursing students in the study group (57.4%) had high level of critical thinking compared to (0%) of those in the control group. Conclusion: There was a significant improvement in nursing students’ metacognition and critical in the study group compared to the control group after the program implementation. Therefore, it is recommended that the faculty of nursing should integrate metacognitive skills training into the nursing curriculum and provide training courses to faculty members on how to develop students' metacognitive skills.