This book is a study that sought to investigate the effects of teachers? appraisal on academic performance in public secondary schools in Starehe Constituency in Nairobi, Kenya. The study sought to find out the nature of teachers? appraisal in the eleven surveyed schools. The study further sought to find out the effects of teachers? appraisal on three aspects of academic performance (grades, tasks performance and class attendance and participation). Primary data was used in the study. The data was gathered using questionnaires administered to teachers and head teachers. The data gathered was analyzed using descriptive statistics (frequencies, percentages and mean scores) and thematic technique where data was grouped according to emerging themes. This was enhanced by a narrative explanation. As the most significant resource in schools, teachers are critical to raise education standards. Improving the efficiency and equity of schooling depends, on a large measure, on ensuring that teachers are highly skilled, well resourced, and motivated to perform at their best. Raising teaching performance is perhaps the policy direction most likely to lead to substantial gains in learning.