The study concerned school planning for girls‟ education in a culture practicing early marriage and it was a case study of Sukuma society in Simiyu region in Tanzania. The aim of the study was to evaluate the effectiveness of school planning in ensuring girls‟ enrollment, attendance and retention in secondary schools in Sukuma society. Again the study looked on how Sukuma perceive education for girls in relation to cultural conflict over girls‟ education. However, the study aimed at shading light on how planning should be organized to influence education for girls in Sukuma society. The study employed qualitative research where as ethnographic case study was the research design. The data were collected through main three research methods namely; focus group discussion, informal interviews and participant observation. The study employed 60 participants; these were teachers, students and the members of the community surrounding four secondary schools in a Sukuma speaking district of Busega in Simiyu region. However, the researcher was the main key participant for participant observation and the main role was observer as participant. The findings indicated that Sukuma people do not give much priority on education for girls and the main perception was that, taking girls to school is losing wealth in the family through bride prices. Again, it was observed that schools and governments‟ plans to end early marriages for school girls have failed. It was also found that school planning for girls‟ education can be effective through schools by using strategic and operational plans to be organized by schools. From the above findings, the study recommends to rectify the situation through school community partnerships by considering the local community as inputs towards schools‟ success through planning process