This study was conducted to investigate the effects of visual instructional materials on students‟ performance in Agricultural Science of senior secondary schools in Taraba State, Nigeria. Three thousand, one hundred and five students were the target population. The study had a sample size of three hundred and forty-two students in intact classes from the four senior secondary schools in the Northern Senatorial District of Taraba State. The researcher used quasi experimental design. size. The study had four Objectives which include; assess the effect of diagrams on students‟ performance in agricultural science of senior secondary schools, ascertain the effect of maps on students‟ performance in agricultural science of senior secondary schools, identify the effect of specimens on students‟ performance in Agricultural Science of Senior Secondary Schools and compare the effect of diagrams, maps and specimens on students‟ performance in Agricultural Science of Senior Secondary Schools; four research questions; which include, what are the effect of diagrams on students‟ performance in agricultural science of senior secondary schools, what are the effect of maps on student‟ performance in Agricultural Science of Senior Secondary Schools, what are the effect of specimens on students‟ performance in agricultural science of senior secondary schools what are the effect of diagrams, maps and specimens on students‟ performance in Agricultural Science of Senior Secondary Schools and four null hypotheses were formulated in line with the research objective. The pretest and posttest items were fifty (50) used as instruments for data collection before and after the treatment, respectively. The descriptive statistics was used to analyze the research questions, while inferential statistics was used to test the four null hypotheses at 0.05 level of significance. Results of the null hypotheses show that, the four null hypotheses were all rejected. Criteria for the selection of Visual Instructional Materials includes; need of the learners, objectives of the lesson, Teacher capability, size of the class, Knowledge, authority and Appropriateness of the visual instructional materials, Scope of the learners and visual materials. Among the findings of the study were that; there was a significant difference on the mean performance of experimental group taught anatomy and physiology of farm animal‟s concepts using diagrams in agricultural science and those taught without diagrams among senior secondary school students; there was a significant difference on the mean performance of the experimental group taught animal nutrition concepts using specimens in agricultural science and those taught without specimens among senior secondary school students. As a result of the findings from this study, it was concluded that the use of visual instructional materials in teaching and learning of Agricultural science in senior secondary schools in Taraba State was very effective as it enhanced students‟ performance in test administered on them. The following recommendations were made, the teachers should ensure that, they are always using diagrams in teaching anatomy and physiology of farm animals and other related concepts in Agricultural Science as this simplify and clarify what is complex and difficult to explain in words. As a skilled based subject, the teacher should always expose students to different types of specimens that will motivate them to think critically as well as to stimulate and sustain their interest throughout the period of lessons.