Marital instability has impacted the development as well as the social functioning of a number of children in Nigeria. This study therefore examined the influences of marital instability on students’ school adjustment in Benin metropolis, Edo State. The descriptive research survey was adopted for this study. A random sample size of 462 secondary school students was selected using the stepwise random method. The findings revealed that students from broken homes have difficulty adjusting to their schooling due to their school class or level, which showed least score with mean value of 2.85, followed by parental level of education mean value of 2.87, parental socio-economic status, with highest mean value of 3.12 and students gender with p value of .114 of marital instability. It is recommended that crucial consideration is needed by helping professional, such as social workers, teachers, guidance counselors, family counselors and child protection networks to promote the academic functioning of students of separated or divorced parents.