According to UNESCO, school-related gender-based violence (SRGBV) involves acts or threats of sexual, physical, or psychological violence occurring within and around school, perpetrated because of gender norms and stereotypes, and facilitated by unenforced and unequal power dynamics. These acts or threats not only have detrimental effects on the academic outcomes of their victims but also more specifically, hinder a country's human, social, psychological, and economic development in addition to obstructing the government's poverty alleviation and peace building efforts. This study is a part of cross-country research conducted with other scholars in four countries--Jamaica, Kenya, Malawi, and Nigeria--to determine the prevalence and pattern of SRGBV in public primary schools and to contribute more broadly to knowledge of about SRGBV in primary schools. The general objective of the study was to ascertain the extent of gender-based violence (GBV) among primary school pupils. The study has the following specific objectives: (1) Determine the prevalence and gender disparity of SRGBV in public primary schools in Nigeria; (2) Identify the location and timing of SRGBV in public primary schools; (3) Explore possible risk factors for SRGBV in public primary schools; (4) Reveal the identifiable patterns or forms of SRGBV in public primary schools; (5) State the impacts of SRGBV on public primary school pupils; (6) Identify the level of training of public primary school teachers in handling SRGBV; and (7) Evaluate the existence and effectiveness of school-based programs on SRGBV. The research applied a mixed methods design, including quantitative surveys and qualitative focus group discussions. Key messages from the research findings include: (1) Prevalence of SRGBV in primary schools in Nigeria is high, and both girls and boys are subject to it; (2) SRGBV is usually perpetrated by familiar people in secluded places; (3) Pupils lack appropriate support structures or reporting mechanisms to address SRGBV; and (4) Inadequate school-based programs exist to curb SRGBV. [There are three other reports in this series: Kenya (ED614132), Jamaica (ED610693), and Malawi (ED614033).]