The integration of scientific research into medical curricula remains insufficient despite its advantages for medical students’ professional development and the advancement of medicine. This study aimed to evaluate the impact of first-year medical course attendance on medical students’ attitudes and perceptions towards scientific research and clinical practice, while also assessing the contribution of sociodemographic and academic factors. Two hundred and thirteen medical students self-administrated a questionnaire at the beginning and at the end of the first school year. Their responses were compared and two regression models were calculated to assess factors influencing students’ attitudes and perceptions. After freshman year, students displayed significantly lower positive attitudes towards science and research. Their motivation to perform research and to integrate it into the curriculum also decreased, while the importance attributed to research skills for clinical practice increased. Motivation to perform research and negative attitudes were positively and negatively associated with grade point average (GPA), respectively. Female students and those who attended public secondary schools attributed greater importance to communication skills. This study reinforces the need to early develop research skills and positive attitudes in medical students, motivating them to become physician-scientists. Additional follow-up studies may offer further contributions to the integration of research into medical curricula.