This study explored the impact of teacher – student's relationship on academic performance in Tanzania using a case study design. The study was conducted to: (a). identify the components of the teacher – student relationship that are essential to the teaching and learning profession (b) determine the contribution of teacher-student relationships to academic performance in public secondary schools in Magu District in Tanzania. (c) identify the challenges encountered by students who miss teacher-students relationship in public secondary schools in Magu District. (d) establish possible measures which could be used to boost teacher-student relationships . The respondents in this study were 130 that were drawn from 6 public secondary schools, 6 school Heads, 57 teachers, 66 students and one District Educational Officer. A mixed approach was used in this study. In order to get information, the researcher used questionnaires and interviews as instruments. The results of this study indicated that teacher –students‟ relationship is a crucial determinant and catalyst to academic performance in Tanzanian public secondary schools. The study discovered that students and teachers knew the components of teacher – students relationships. The study identified that teacher students relationships helps students to feel cared by their teachers, helps students to have freedom of expression in the classroom and help teachers and students to be an integral part of the classroom as they participate actively. Also the study discovered that there are some challenges facing negative teacher – student ratio such as poor performance of students, school deropout, immoral behavior, loneliness, stress and lack of confidence. From these findings the researcher concluded that despite teachers and students were aware on the elements of teacher- students relationships but still there were poor teacher – student relationships in schools. Therefore, the study recommended that, teachers should introduce close relationshis with students. Also, the study recommended that, performance of students can only be attained if teacher – students relationships will be maintained.