Background: Scientific excellence is one of the most fundamental underpinnings of medical education and its relevance is unquestionable. To be involved in research activities enhances students' critical thinking and problem-solving capacities, which are mandatory competences for new achievements in patient care and consequently to the improvement of clinical practice. Purposes: This work aimed to study the relevance given by Portuguese medical students to a core of scientific skills, and their judgment about their own ability to execute those skills. Methods: A cross-sectional study was conducted on students attending the first, fourth and sixth years of medical course in the same period. An assessment instrument, exploring the importance given by Portuguese medical students to scientific skills in high school, to clinical practice and to their own ability to execute them, was designed, adapted and applied specifically to this study. Results: Students' perceptions were associated with gender, academic year, previous participation in research activities, positive and negative attitudes toward science, research integration into the curriculum and motivation to undertake research. The viewpoint of medical students about the relevance of scientific skills overall, and the ability to execute them, was independently associated with motivation to be enrolled in research. Conclusions: These findings have meaningful implications in medical education regarding the inclusion of a structural research program in the medical curriculum. Students should be aware that clinical practice would greatly benefit from the enrollment in research activities. By developing a solid scientific literacy future physicians will be able to apply new knowledge in patient care.