Background: Variations in the results of research on the association between learning preferences, personality traits, and academic achievement have been reported. The aim of this cross-sectional study was to determine the relationship between the first-year academic achievement of medical students and their learning styles and personality traits. Methods: Preclinical medical students completed a questionnaire assessing sociodemographic data and course grades, as well as the Index of Learning Styles and the International Personality Item Pool 50 questionnaires. The indicator of academic achievement was the grade point average (GPA) of first-year courses. Main findings: The majority of students were well balanced in the active/reflective and sequential/global dimensions. Almost 70% of students showed a preference for sensing in the sensing/intuitive dimension. In the visual/verbal one, there was a shift toward visual learning, since only slightly over 2% of students preferred the verbal type. Male students had a preference for the intuitive style, while female ones favored sensing learning. GPA was not affected by sex or residency status. There were no significant differences in GPA between the examined learning preferences. There were no major correlations between the examined personality traits and GPA. Principal conclusions: This study did not provide evidence of significant interrelation between the learning preferences, personality traits, and academic achievement of preclinical medical students.