Objective: to compare the levels of general critical thinking and the skills or cognitive attributes involved, individually measured during the training of undergraduate nursing students, through a teaching intervention using Concept Maps. Method: an experimental, randomized, double-blind study with before and after design, conducted with 77 undergraduate nursing students. The research subjects were randomized to the control (38) and experiment (39) groups and both participated in a course on Advanced Life Support in Cardiology for a period of five weeks, when the intervention was the construction of four concept maps. Data collection took place through a sociodemographic questionnaire and the California Critical Thinking Skills Test (CCTST) before and after the course and after in order to measure critical thinking. Results: sociodemographic data confirmed that the groups had similar characteristics. After the intervention using the concept maps, the mean pre-and post-test general critical thinking averages were classified as moderate and showed no statistically significant difference. The t-test for paired samples showed a significantly increased Evaluation skill score (p-value of 0.022) in the posttest for the experiment group. Conclusion: the use of the teaching strategy with construction of the concept maps performed well in the promotion of General Critical Thinking and its abilities. Teaching strategies based on constructivist theories should be encouraged as they play a significant role in improving student learning and critical thinking.