Medical students’ critical thinking skills were enhanced dramatically in all subscales, except for inference and deductive reasoning. In our study, the highest scores were seen for the analysis, inductive reasoning, and evaluation subscales. Smith et al. [
10] found a significant improvement in analysis skills, while scores for the induction subscale sharply decreased. Furthermore, the findings of the current study do not support those of other previous studies. Jacob [
11] reported that, after using online discussion forums, critical thinking skills showed the most noticeable improvements in the inference and deduction subscales. Chen et al. [
12] reported that despite a significant increase in the critical thinking score in the intervention group, only the inference domain showed a significantly higher adjusted mean score. Although these disparities in results can be partially explained by differences among studies in terms of the context, and participants, it may be interpreted that our program and environmental factors can contribute to a consequence that does not support growth of these skills. However, another possible explanation for this is that the medical education program at TUMS emphasized students’ capacity to analyze and engage with arguments. In other words, aspects of our program may not have supported growth in students’ hypothesis-testing and inference skills. In this study, no significant differences were found between the scores of male and female students. A similar study was performed at Isfahan University of Medical Sciences during 2008-2010, using the same questionnaire to assess the critical thinking skills of medical sciences students for 2 sequential semesters, and found some similar results, including the lack of a difference between genders in total scores and relatively high scores for deductive skills [
13]. However, they reported no significant improvements, and in that sense, the findings of the study are quite dissimilar to those of the present study [
13]. The findings of the current study are consistent with those of Aziz-Fini et al. [
14] and Liu et al. [
15], who found no significant relationship between nursing students’ score in critical thinking skills and their age and gender.