Dissertation (MA Education)The main purpose of this study was to find out the influence of peer groups on students’ learning performance. It employed a mixed method approach and exploratory research design. The data were collected using questionnaire, interview and focus group discussion from two higher education institutions found in Dodoma region, Tanzania. A total number of 137 participants were involved in the study to include 2 students’ counselors and 135 students. The study employed purposive sampling to obtain students counselors and stratified random sampling to obtain students. The findings have revealed that there are different forms of peer groups that exist in HEIs such as learning, sports and games, religious groups and socialization groups. It was observed that students highly belong in learning, sports and religious group combination when in HEIs. Secondly, it was revealed that the type of peer groups that students belong influenced the students learning behavior, as the p-value was <0.05, which proved significant. Thirdly, the study findings revealed the rank of discipline condition of HEIs found normal. It was evidenced that there was a significant difference to those students belonging to deviant groups and those who do not belong to deviant groups in matters of discipline. Fourthly, it was revealed that the type of peer groups that students belong have a significant relationship with students learning outcome at p value <0.05. However, the findings revealed that peer groups influence students learning outcome in terms of knowledge, skills, values, ability and moral traits. Finally, the study recommends that students in HEIs should choose wisely the kinds of peer groups they decide to engage with as they determine their learning performance. Also, there should be seminars, workshops and peer education awareness programs in HEIs that would help students in understanding the issues of peer groups and how to use such peer groups in promoting their learning performance.