Background: In today, nursing is a highly complex and challenging profession that exists within a rapidly changing health care environment, nursing students should be active learners and think critically about providing secure patient care. The capacity to think critically is also an important component of higher education and more specifically of education. The present study aimed to assess the effect of critical thinking training program on improving knowledge and skills of nursing students. Subjects and methods: A quasi-experimental design was used to conduct the present study. A stratified proportionate random sample of 267 students was chosen from technical institute of nursing in Suez Canal University that enrolled in the academic year 2019-2020. Data were collected using two tools namely; Critical thinking knowledge questionnaire and California critical thinking skills scale. Results: all nursing students (97.4%) had unsatisfactory knowledge of critical thinking before the program implementation. While, the highest percentage of nursing students (100%) had satisfactory knowledge of critical thinking after the program implementation. The highest percentage of nursing students (86.1%) had a low level of critical thinking skills before the program implementation.  While, slightly less than half of nursing students (48.7%) had a high level of critical thinking skills after the program implementation. Conclusion: there is no statistically significant correlation between total scores of critical thinking knowledge and skills among students before the implementation of the training program. It recommended that nurse educators should develop continuous in service- training and education program for refreshing and increasing nursing students' knowledge and skills about concept of critical thinking.