This research explores and compares two leadership behavioural styles -- relations- and behavioural styles -- of school leaders in Finland. This study aimed to explore and understand the behavioural style of school leaders, specifically related to relations-oriented and task-oriented behaviour. Three schools in Finland were selected. In-depth interviews were conducted with school principals, as school leaders, and other school actors, such as vice principals, teachers, special-education teachers, and administrative staff members. The results suggest that leadership behavioural styles in terms of relations-oriented and task-oriented behaviour are equally important for accommodating changes and development in schools. The results suggest that relations-oriented behaviour was preferred by those who had been in the organisation for a longer time. The task-oriented behavioural style was found to be adopted when changes were required by the municipality (school district), which needed to be urgently addressed to meet the current requirements for school infrastructural development and changes in the educational system. In addition, the school leaders with task-oriented behaviour were more effective, while leaders with relations-oriented behaviour were efficient and generated social harmony. These findings suggest that contextual variations enabled flexibility in leadership behavioural style.