The purpose of this study was to establish if there is any significant relationship between Principals’ time management as an independent variable and administrative tasks’ performance as the dependent variables in Lagos State Junior and Senior Secondary schools. The study divides administrative tasks into five broad headings, namely: school personnel task, school instructional supervisory task, school business task, school plant maintenance task and school public relations task. Two instruments were used for this study titled, Time Management and School Administrative Tasks’ Performance Questionnaire I (TMSATPQ I for Principals), the second instrument, Time Management School Administrative Tasks Performance Questionnaire II (TMSATPQ II, for teachers). 446 Principals and two thousand, two hundred and thirty Teachers (2230) at five teachers (5) per school. The Sampling cut across the six education districts of Lagos State. The instruments were validated and found reliable at r = 0.83 and r=0 .78 respectively. It was however discovered that there is no significant relationship among principals’ time management, school personnel task, experience and qualification. While, principals’ time management has not significantly affected the instructional supervisory task, school business task, experience and qualification put together. Also, there is no significant differences between principals’ who are cyclic in task performance and principals’ who linear in time performance. Recommendations were made based on these findings, some of which are that conscious effort should be made to identify where, how, when, and why time is wasted and eliminate them. Principals are also encourage to set deadlines and use a day runner complete with a check list to evaluate at the end of each day the level of task completion and strategize for days ahead in meeting the set deadlines and that principals should use the principles and practices of delegation of responsibility and t