Background/purpose: This study analyzed the contribution of three mentorship practices relatively and cumulatively to the research productivity of early-career academics in the field of educational psychology in universities. The study was conducted in the South-South region of Nigeria. Materials/methods: The research method adopted was the quantitative approach, following the ex-post facto research design. The study's population covered 723 early-career researchers (ECRs) in educational psychology distributed across 19 universities located in South-South Nigeria. The "Mentorship Practices and Research Productivity Questionnaire" (MPRPQ) was the instrument used for data collection. The questionnaire was designed by the researchers and then validated by three experts. Reliability analysis was performed using the Cronbach approach with estimates of 0.80, 0.79, 0.87, and 0.91 obtained for the four clusters. Primary data were collected from the field after copies of the instrument had been administered to respondents. Results: Mentorship practices were generally revealed to significantly contribute to the research productivity of ECRs in educational psychology in universities. Specifically, the adoption of cloning and apprenticeship approaches to mentorship contributed substantially to the ECRs' research productivity. However, the study highlighted that nurturing contributed only negligibly to the ECRs' research productivity. Conclusion: Mentorship practices are important determinants to the research productivity of early-career educational psychologists. In order to boost the productive research capacities of ECRs, there is a need for institutions to strengthen their mentorship practices.