The study assessed the in-service learning paths that could maximize teachers’ attitude towards and efficacy in implementing inclusive education among primary education teachers in Ile-Ife Metropolis, Southwestern Nigeria. The three in-service learning paths considered were postgraduate degree, school-based training and experience with inclusive classroom. The study adopted the ex-post facto research design. The sample comprised 200 primary education teachers who were selected using simple random sampling technique. Results obtained revealed that none of each of the three learning paths significantly influences either the attitude of the teacher towards or their efficacy in implementing inclusive education practices. It was also revealed that the combinations of postgraduate degree, experience with inclusive classroom and school-based training on inclusive classroom ranked first in maximizing both efficacy and attitude of the teachers while experience with inclusive classroom combined with school-based training on inclusive education ranked second in maximizing both attitude and efficacy. The combination which ranked least (4th) for efficacy was postgraduate degree with experience with inclusive education while the combination which ranked least for attitude was postgraduate degree with school-based training on inclusive education. The implications of these findings is that stakeholders in the development of human capital in the basic education sector in developing countries should continue to seek and use appropriate mix of continuing professional development paths that maximizes resources and the expected outcomes in teachers while minimizing costs. One of the limitations of the research is its scope which utilized teachers in a town in one of the states in Southwestern Nigeria. Future studies may consider the use of larger samples from various geopolitical zones and the use of robust statistical tools such as structural equation modelling to determine the interplay of personal, work-related variables and selected continuing professional development strategies on teachers’ outcomes in implementing inclusive education practices.