Dissertation (MSc Statistics)In Tanzania secondary education, evaluating of students’ performance is a problem. In this study, students’ academic performance from six secondary for four years were assessed by using Statistical Quality Control (SQC). Data collected for the study, were secondary data from academic documents which were students’ progressive report. Statistical quality control charts were used to analyze data collected. After evaluating out of 14 of Individual control charts, 12 charts were found to be out of statistical control. Out of the 19 of mean control charts all 19 charts were out of the statistical control. For the group control charts indicated that out of 6 charts all 6 out of them also, were out of the statistical control. Therefore, secondary school students’ performances were shown to be out of statistical control, which implied that, there were assignable courses of variations operating in the students’ performance, which should be detected and corrected. However, if students’ performance for the four years of study fell within the control limits, then we could conclude that the students had maintained the desired target performance value. The study recommends that, school administrators and instructors should identify and remove causes for the students’ performance, which were falling below the lower control limit which indicated a negative shift in performance and implements factors of the students’ performance whom fell above the upper control limit and indicated the positive shift in performance.