The study by Léo F. C. Bruno, a professor of leadership at Fundação Dom Cabral in Brazil, evaluates the personal values profile, predominant leadership styles, leadership effectiveness, and their relationships with organizational differentiation among Brazilian executives from various organizations. The research uses a rank-order instrument to assess personal values, an existing market instrument to identify leadership styles, and linear regression to analyze the relationships between personal values balance, leadership effectiveness, and organizational differentiation. The study found that executives have an unbalanced personal values profile, with a predominance of economic and theoretical values. They also lack flexibility in leadership styles, favoring selling and sharing ideas. Leadership effectiveness was moderate, and there was a high positive correlation between personal values balance and leadership effectiveness, as well as between these variables and organizational differentiation. The study recommends addressing leadership education from early childhood, promoting leadership democratization, and conducting larger, cross-cultural studies to improve leadership development.The study by Léo F. C. Bruno, a professor of leadership at Fundação Dom Cabral in Brazil, evaluates the personal values profile, predominant leadership styles, leadership effectiveness, and their relationships with organizational differentiation among Brazilian executives from various organizations. The research uses a rank-order instrument to assess personal values, an existing market instrument to identify leadership styles, and linear regression to analyze the relationships between personal values balance, leadership effectiveness, and organizational differentiation. The study found that executives have an unbalanced personal values profile, with a predominance of economic and theoretical values. They also lack flexibility in leadership styles, favoring selling and sharing ideas. Leadership effectiveness was moderate, and there was a high positive correlation between personal values balance and leadership effectiveness, as well as between these variables and organizational differentiation. The study recommends addressing leadership education from early childhood, promoting leadership democratization, and conducting larger, cross-cultural studies to improve leadership development.