Purpose: The research objective was to examine to what extent line manager competencies are linked to intelligence, and more specifically, three types of intelligence: analytical (fluid), practical and emotional. Methodology: The research was carried out with line managers (N=98) who took part in 12 Assessment Centre sessions and completed tests measuring analytical, practical and emotional intelligence. The adopted hypotheses were tested using a multiple regression. In the regression model, the dependent variable was a managerial competency (management and striving for results, social skills, openness to change, problem solving, employee development) and the explanatory variables were the three types of intelligence. Five models, each for a separate management competency, were tested in this way. Findings: In the study, it was hypothesized that practical intelligence relates to procedural tacit knowledge and is the strongest indicator of managerial competency. Analysis of the study results testing this hypothesis indicated that practical intelligence largely accounts for the level of competency used in managerial work (from 21% to 38%). The study findings suggest that practical intelligence is a better indicator of managerial competencies among line managers than traditionally measured IQ or emotional intelligence. Originality: This research fills an important gap in the literature on the subject, indicating the links between major contemporary selection indicators (i.e., analytical, practical and emotional intelligence) and managerial competencies presented in realistic work simulations measured using the Assessment Centre process.