This study examined managing resource wastages as predictors of effective secondary school administration in Anambra State, Nigeria. The study was guided by three objectives and a corresponding research questions and null hypotheses. The study adopted a correlation survey research design. The population of the study comprised of all the 762 Principals and Vice Principals in 254 public senior secondary schools in Anambra State. A simple random sampling technique was used to select a sample 385 respondents representing 50% of the entire population of this study. The research instruments titled: Managing Resources Wastages Scale (MRWS) and Effective Secondary School Administration Scale (ESSAS) were used for this study. The face and content validities of the instrument were established by the researcher. Cronbach Alpha statistics was used to test for the reliability of the instruments which the coefficients of Managing Resources Wastages Scale and Effective Secondary School Administration Scale are 0.84 and 0.88. The reliability coefficients for the subscales of Financial Resource Wastages, Human Resource Wastages and Infrastructural Resource Wastages are 0.82, 0.81 and 0.87 respectively. The findings of the study revealed that that that the strategies for managing financial resource wastages and human resource wastages to a high extent predict effective secondary school administration in Anambra State. However, strategies for managing infrastructural resource wastages to a low extent effective secondary school administration in Anambra State. Based on the findings, it was recommended among others that chool administrators should strengthen their effort in managing financial resource and keep record track of their expenditure to avoid linkages and wastages in the system for effective secondary school administration.