Teacher motivation is a critical determinant of instructional quality, professional commitment, and overall educational outcomes, particularly in rural and resource-constrained contexts. In rural Uganda, secondary school teachers face challenges such as inadequate instructional materials, poor infrastructure, low salaries, and limited professional development opportunities, which affect service delivery. This study examines the role of intrinsic, extrinsic, and professional growth motivational drivers in shaping teacher service delivery. Guided by Herzberg’s Two-Factor Theory (1959, 1966) and Vroom’s Expectancy Theory (1964), a mixedmethods design was employed, including surveys of 120 teachers and interviews with 15 teachers and 10 headteachers. Findings reveal that while intrinsic and extrinsic factors influence service delivery, professional growth motivation is the strongest predictor. Teachers engaged in continuous professional development demonstrate improved instructional competence, classroom management, assessment practices, and professional commitment. The study recommends strengthening professional development structures, linking career progression to skill acquisition, and improving working conditions to enhance teacher performance in rural Uganda.