This paper empirically tests the impacts of company size, measured by total sales revenues, on the importance of 12 essential leadership functions, (e.g., encouraging teamwork), six skills (e.g., interpersonal), seven traits (e.g., being decisive), four leadership styles -participatory, directive, tasks oriented, and employee oriented, and on leadership effectiveness.The findings evidence patterns of leadership at larger companies that are significantly different from smaller companies. The collective findings make a compelling argument that increasing company size reduces the importance of leaders engaging and interacting with followers. This likely reflects characteristics of larger companies that lessen the importance of or substitute for employee engagement and interpersonal interactions. However, the leadership at larger companies was not found to be less or more effective. The study also found that larger companies are more risk averse, which has additional implications for leadership. The findings have a number of implications for practitioners, researchers, and faculty teaching leadership.