This analysis explores the relationship between transformational, transactional, and laissez-faire leadership styles with staff work engagement at the department level in the public sector in Vietnam. Using a cluster sampling method, a total of 378 participants were selected and agreed to participate in a survey by completing a questionnaire on the relationship between leadership style and work engagement. All participants are attendees of a training course for department-level leaders at the School of Culture, Sports, and Tourism Administration Officers under the Ministry of Culture, Sports, and Tourism of Vietnam. A regression was run on the collected data to test the hypothesis on the relationship between leadership styles and staff task performance. The regression results show that there is a significant indirect relationship between staff work engagement and innovative work behavior and task performance. In addition, there is a relatively positive relationship between the transformational leadership style and transactional leadership style of the department-level leaders in the Vietnamese public sector with staff work engagement, particularly innovative work behavior and task performance. On the contrary, laissez-faire leadership style negatively impacts staff work engagement and innovative work behavior. Staff work engagement is an integral part of the relationship between leadership style and leadership effectiveness. The findings suggest that the Vietnamese public sector should aim to identify transformational and transactional leaders. This research focuses on the department level and is limited to three leadership styles (transformational, transactional, and laissez-faire) only. Future research therefore can expand the scope to higher levels than the department leaders.