This paper identified poor condition of services, irregular promotion and payment of salaries, poor professional training, societal negative influence, inadequate facilities and instructional supervision as causes of indiscipline among teachers in Nigeria. It also identified increase in examination malpractices and dropout rate, fall in instructional quality, moral value, poor quality students for higher education leading to decrease rate of national development as impacts of teachers indiscipline on school administration. Recommendations on ways of reducing teachers indiscipline in Nigeria schools was also highlighted.