Critical thinking in present times is a profoundly esteemed instructive outcome after an educational course or program particularly corresponding to higher level of professional training. Quasi-experimental study was conducted to assess the effectiveness of concept mapping versus traditional method of instruction as a tool to enhance critical thinking among nursing students in medical surgical nursing (cardiovascular system). Pre-test and post-test control group design was used. B.Sc Nursing III year students were included as experimental group (n=97) and comparison group(n=94). The experimental group was initially given a session on concept mapping and its uses in nursing education. For both the groups instruction on cardiovascular conditions using concept mapping and traditional method was administered respectively. The experimental group and comparison group were assessed for the critical thinking ability using structured questionnaire. The concept maps were evaluated using McMurray’s method scoring criteria. The findings of the study suggest that the difference between pre-test and post-test mean knowledge scores in Concept mapping (variables- analysis, synthesis and evaluation) was found to be significantly higher than the traditional group at 0.05 level. There was significant improvement in construction of concept maps in criteria related to breadth, interconnectivity, and linkage. Majority of students coined the opinion which indicates high level of acceptance that ranges between 90 to 100%. It was concluded that concept mapping is an innovative strategy for enhancing critical thinking ability in nursing students.