This study examined psychological factors influencing upper primary pupils’ acceptance of the competency-based curriculum (CBC) in public primary schools in Aba South Local Government Area, Abia State, Nigeria. The implementation of the CBC has marked a significant shift from content-driven to learner-centered education, emphasizing skill acquisition, critical thinking, and practical application. However, the success of this curriculum reform largely depends on pupils’ psychological readiness and positive engagement with the new teaching-learning processes. Grounded in Social Cognitive Theory, the study investigated key psychological factors including self-efficacy, learner motivation, and attitude toward learning that may affect pupils’ acceptance and adaptation to the CBC. A descriptive survey design was adopted, and a stratified random sampling technique was used to select 300 upper primary pupils (Primary 4 to 6) from six public primary schools in Aba South LGA. Data were collected using a researcher-developed questionnaire validated by experts in educational psychology and curriculum studies, and analyzed using descriptive statistics and multiple regression analysis. The findings revealed that self-efficacy, learner motivation, and positive attitudes significantly influence pupils’ acceptance of the competency-based curriculum. Specifically, pupils with higher self-efficacy and motivation demonstrated greater engagement, understanding, and acceptance of CBC instructional approaches. The study concluded that psychological readiness plays a critical role in the effective implementation of the competency-based curriculum at the primary school level. It recommended that educational stakeholders including curriculum planners, school administrators, and teachers provide supportive learning environments that enhance pupils’ confidence, foster intrinsic motivation, and cultivate positive attitudes toward the curriculum. Additionally, regular psychological support and orientation programs should be instituted to facilitate smoother adaptation to curriculum innovations. The findings contribute valuable empirical evidence to the literature on curriculum implementation and learner psychology, particularly within the Nigerian educational context.