Mathematics is the foundation for the economic and technological development of any nation. It has been asserted that Mathematics is expected to help in accelerating the socio-econo-techno progress of any society. The purpose of this paper is to find out the correlation between the utilization of instructional materials and Grade 6 learners' performance in Mathematics in Buffalo City. Despite the importance of Mathematics as the gateway to the world of science and technology, Mathematics is also regarded as the subject in which many learners underperform. The study adopted a correlational research design and a quantitative approach. The target population of this study was Grade 6 learners in the Buffalo City district. Stratified sampling was used to select 1225 Grade 6 learners. The findings showed that there is a significant relationship between the availability and utilization of instructional materials and Grade 6 learners' performance in Mathematics in Buffalo City (r = 0.999; p>0.05). There is no significant difference between gender and Grade 6 learners' Mathematics performance at Buffalo City (t = -.217, df = 1218, p>0.05). The mean difference between male learners ( =12.820, SD = 3.969) and female learners ( =12.872, SD=4.098) was negligible. It was observed that where materials are available, the management, selection, and effective use are lacking. It is recommended that teachers should not only be encouraged on the use of instructional materials but also be capacitated and guided on the effective use, management, improvisation, and selection of relevant and appropriate materials.