The study investigated the impact of instructional graphics on secondary school student's interest and performance in Christian religious studies in Onitsha Nigeria. This research work grew out of the complaints of teachers and students on the alarming rate at which CRS subject has dwindled because of the way its being taught and this led to poor performance and lack of interest in CRS. The population of the study comprised all the Junior secondary schools in Onitsha metropolis. Stratified sampling was used to select one school each from Onitsha South and Onitsha North constituency which served as the experimental group intact class was used. The experimental group was taught using the instructional graphics package while the conventional method was taught with chalkboard and textbook. The experimental and control groups were taught for six weeks. Two instruments was used for data collection namely: students' Christian Religious Knowledge Achievement Test which comprised of 20 items and the Extent of interests in learning with instructional graphic package questionnaire. The instruments was validated by experts in relevant field, the pilot study was conducted in two schools which are not among the sample schools. Pearson Product Moment Correlation Coefficient and Cronbach reliability method was used and the instruments were found reliable at 0.84 and 0.89 respectively. The two groups were given the SCRKAT typed in white paper as a pretest and it lasted for 60 minutes, the experimental group was exposed to treatment that is learning with instructional graphics package. After the treatment, the same instrument that was used for pre-test was retyped in yellow-coloured paper as post-test and it lasted for 60 minutes. Mean and standard deviation was used to answer the research questions while Mann Whitney and independent t-test was used to test the hypotheses at 0.05 alpha level. Result showed that students taught with instructional graphics package performed significantly higher (83.45) than those taught with the conventional method of chalkboard and textbooks (51.42). The use of instructional graphics package significantly improved the academic performance of students in Christian Religious Studies and should be encouraged in place of the conventional method of teaching for improvement in performances among students in junior secondary schools by teachers.