The article focuses on the issue of the leadership competence of the heads of progymnasiums as a factor in making schools more effective. Progymnasium is part of the Lithuanian system, an institution of general education (Forms 1 to 8), an intermediate link between an elementary school and gymnasium, which differs from basic school in higher quality of activity, the created added value, and pupils’ learning achievements. Quantitative research was conducted with the participation of 193 progymnasium teachers. The research revealed that the leadership competence of the heads of progymnasiums significantly contributed to making schools more effective in terms of participation in projects, favourable conditions for teacher initiatives, participation of community members in the self-evaluation process, creating conditions for teacher professional development, supporting and promoting initiatives, initiating the process of progress and achievement assessment, ensuring the coherence of the mission, vision, and values of the educational institution, the involvement of parents /guardians/ caregivers, promotion of communication and collaboration between community members, and the maintenance of sustainable relations with social partners. The obtained research findings are to be considered as relevant for seeking active expression of leadership of the school authorities and teachers and making progymnasiums more effective.