This study examined administrative challenges and principals’ managerial effectiveness in Ogun State secondary schools. The study population was 13,123 teachers in the state’s secondary schools from which a sample of 900 teachers was drawn from 35 schools using simple random and proportionate random sampling techniques. A self-developed instrument tagged Administrative Challenges and Principals’ Managerial Effectiveness Questionnaire (ACPMEQ) was used to gather information from the respondents. The instrument was validated with a reliability coefficient of 0.78. The hypotheses were tested using Pearson’s Product Moment Correlation at 0.05 level of significance and the outcome revealed that a significant relationship exist between administrative challenges and principals’ managerial effectiveness as well as well-equipped school libraries and managerial effectiveness of principals. However, there was no significant relationship between incessant teachers’ transfer and principals’ managerial effectiveness. It was equally revealed from the study that finance is the best predictor of principals’ managerial effectiveness while physical facility is the least predictor. Based on the findings, it was concluded that administrative challenges are critical variables of principals’ managerial effectiveness. It was therefore recommended that government should give out its supportive arms by releasing grants to schools as and when due and also allow them to collect meager sum of money either on termly or yearly basis which should solely be spent on developmental projects. It was also recommended that within the limited resources available to schools, principals should endeavour to stock the libraries with necessary textbooks.
Key words: Education, secondary education, administrative challenges and managerial effectiveness.