This study aimed at examining the effects of indiscipline on students’ academic achievement on public secondary schools in Ngara District. The study focused on four objectives; to identify the types of indiscipline among secondary school students, to establish the major causes of indiscipline among secondary school students, to assess the effects of indiscipline on academic achievements, and to find out major ways of alleviating indiscipline among secondary school students. The study was guided by social learning theory by Abert Bandura. The study employed a mixed approach with a convergent parallel design in which 330 participants were selected to give responses in the study. Data were collected through questionnaires and interviews. Data were analyzed by using cross tabulation. Data were tested by chi square with the aid of SPSS 20. Thematic analysis was used to analyze qualitative data. The findings of the study revealed that there are indiscipline cases like bad use of language, engaging in love affairs and involving in theft cases. Also, the findings indicated that there was misuse of internet, poor parenting and the use of ICT equipment as causes of indiscipline among secondary school students. In addition to that it was found out that there is a significant relationship between students discipline and academic achievements. It was indicated that parental involvement was a way of controling students discipline. The study recommended that there must be a better way of controling discipline of the students through the cooperation of heads of schools and community members. It is also recommended that community members should take care of the students for their performance betterment. Furthermore, the study recomends that students should behave well in order to perform well in academics.