The study examined effects of peer-assessment technique on students’ academic achievement and interest in Mathematics in Upper Basic Schools II in Enugu North Local Government Area of Enugu State. The study adopted a Quasi Experimental Research Design and used the pretest – posttest non-randomized control group design. The area covered by this study is Enugu Education Zone of Enugu State. This education zone consists of Enugu East, Enugu North and Isi-uzo Local Government Areas of Enugu State. The population of the study consisted of all the Upper Basic School Two (UBSII) students in Enugu North Local Government Area of Enugu State numbering 5,628 (male = 2,492 and female =3,136). A sample of 120 Upper Basic School II (UBSII) students (58 males and 62 females) was used for the study. The researcher used a multi-stage sampling technique to draw the sample for the study. Two research questions and two null hypotheses guided the study. Mathematics Achievement Test (MAT) and Mathematics Interest Scale (MIS) were used to collect data for the study. The data was analyzed using mean, standard deviation and analysis of covariance (ANCOVA). The result revealed that peer assessment, which is a method of assessment whereby learners are allowed to assess their peers and give feedback based on a given rule had significant effect on students’ academic achievements and interest in mathematics. The study also revealed that peer assessment method is significant in enhancing students’ academic achievement in mathematics. The study further indicated that peer assessment in enhancing male and female students’ interest in mathematics does not differ significantly. Based on the findings of this study, it could be concluded that when Peer Assessment is properly used by teachers, the academic performance and achievement of the students will not only improve but it can also enable the students to better understand and develop keen interest in the contents of the subject. Proper understanding and interest in the contents of the subject will enable the students not only to perform better but enhance academic achievement. The study recommended that peer assessment strategy should be used by teachers in the teaching and assessment of student in mathematics
