In the rapidly changing school environment effective principals are needed to make necessary changes while also developing a culture of shared responsibility and community (Hallinger & Heck, 1998; Leithwood & Jantzi, 1999). The correlation between transformational leadership and emotional intelligence was investigated in this quantitative study of school principals. Also included in the research was the investigation of the relationship between each construct and effectiveness as perceived by their teachers. The research sample was composed of 30 elementary, middle, and high school principals and five to seven teachers who worked with each principal from schools within the United States. An emotional intelligence score for the principals was obtained by administering the Mayer-Salovey-Caruso Emotional Intelligence Test (MSCEIT). Teachers who worked with each principal completed the rater form of the Multi-Factor Leadership Questionnaire (MLQ-5X). This yielded a mean transformational score, a leader effectiveness score, and scores for other non-transformational leadership styles. Correlations were analyzed to conclude that there is a positive relationship between emotional intelligence and transformational leadership, Pearson’s r(30) = .37, p < .05. A positive correlational relationship between effectiveness and both emotional intelligence, Pearson’s r(30) = .38, p < .05, and transformational leadership, Pearson’s r(30) = .90, p < .01, was also evident. Analyzing the relationship between emotional intelligence and different non-transformational leadership styles yielded mixed results. Findings indicate a relationship exists between emotional intelligence and contingent reward leadership, Pearson’s r(30) = .38, p < .05, while no significant relationship was evident between emotional intelligence and other leadership styles. Based on the results of the study, it was concluded that principals and future principals could better develop effective leadership skills by becoming more aware of their strengths and weakness in the area of emotional intelligence, along with improving their transformational leadership behaviors.