The study investigated the impact of instructional materials on pupils’ academic achievement in social studies in Enugu state, Nigeria. The study adopted a quasi-experimental pre-test, post-test control group research design. The study was guided by three null hypotheses tested at 0.05 level of significance. The population of the study comprised 1,223 pupils in all the public primary schools in Enugu state. The sample size for the study was 83 primary 5 pupils selected from two public primary schools using intact classes. Purposive sampling technique was to sample the two schools from where two intact classes were selected. The instrument for data collection was Social Studies Achievement Test (SSAT). The data collected were analyzed using mean and standard deviation. The result of the studies showed that pupils who were taught social studies using instructional materials had better academic achievement than those who were not, and that gender has no significant effect on academic achievement of pupils who were taught social studies using instructional materials. Based on the findings of the study, it was recommended among others that adequate and sufficient instructional material be supplied to primary schools for enhanced teaching and learning of social studies