Throughout the western world a leading example of the educational reforms that have been implemented in the late twentieth and twenty-first century is School-Based Management (SBM), a system designed to improve educational outcome through staff teamwork and self-governance. This research set out to examine the efficacy of teamwork in ten SBM-designated Arab-Bedouin elementary schools in Israel. Two explicit issues were examined: (1) What impact did SBM have on the development of teamwork among the schools' staff? (2) Does the Arab-Bedouin social-cultural context influence implementation of teamwork in SBM schools? The research method consisted of a questionnaire to which 361 teachers/school principals replied, and a semi-structured interview with 30 of the respondents. Results of this study demonstrate that true teamwork does not exist in the schools studied, despite their SBM official status, primarily because the concept of teamwork clashes with the social/cultural norms of traditional Arab-Bedouin society and thus exacerbates conflicts among staff, which then impedes implementation of SBM. In conclusion, this research recommends that for SBM to enable traditional Arab-Bedouin society to benefit from managing its own schools, broad educational changes such as this must be introduced gradually, in a customised, culturally sensitive manner.