The study was carried out to examined the effect of instructional materials and secondary school students’ attitude and performance in Mathematics in Mkpat Enin Local Government Area. The study design was a quasi-experimental research design. The participant population consisted of all the 1840 junior secondary two Mathematics students in the 16 public secondary schools in Mkpat Enin Local Government Area. The sample for the study was 93 JS 2 Mathematics students. Simple random sampling technique was used to select two (2) schools out of sixteen (16) public coeducational schools in the study area. The instruments used for the study were “Mathematics Performance Test (MPT) and Mathematics Attitude Questionnaire (MAQ)”. The instruments were validated by two Mathematics lecturers and an expert in Measurement and Evaluation in the Department of Science Education, Akwa Ibom State University. A reliability coefficient of 0.83 and 0.78 were obtained for the MPT and MAQ using the KuderRichardson 20 formula and Cronbach respectively Descriptive statistics, specifically the mean and standard deviation, were employed to address the research questions, whereas the hypotheses were analysed using an independent t-test. Findings revealed a statistically significant improvement in both performance and attitude among students taught linear equations with instructional materials compared to those who received instruction without such resources. The findings also indicated that male and female students exhibited comparable attitudes and performance when taught linear equations with instructional materials, showing no statistically significant gender difference. From these results, the study concludes that the effective integration of instructional materials substantially improves students’ attitudes and achievement in Mathematics within Mkpat Enin Local Government Area. Consequently, it is recommended that school administrators promote the consistent use of appropriate instructional materials by teachers to enhance learners’ engagement and academic outcomes.