The study was carried out to determine the "Effects of Demonstration and Discussion Methods on Senior Secondary School Students Academic Performance in Agricultural science in Kaduna State". Five objectives, five research questions and five null hypotheses were raised to guide the study. Relevant literatures were reviewed on the key variables of the study. The study adopted quasi experimental design in which pre-test and post-test were used. The target population for the study was made up of forty-nine thousand five hundred and sixty-one (49,561) public Senior Secondary Schools Two (SSII) students who were offering Agricultural Science in the twelve (12) Educational Zones in Kaduna State. The sample size for the study was one hundred and thirty three (133) from three (3) intact classes of Senior Secondary Schools Two (II) Students offering Agricultural Science in Kafanchan Education Zone. The sample was arrived at using purposive sampling technique. The instrument that was used for data collection in this study was a 40-item "Agricultural Science performance Test" (ASPT) designed by the researcher. The validated ASPT was pilot tested and split half on Statistical Package for Social Science (SPSS) using Spearman Brown Formula and a reliability index of 0.78 was obtained. The data obtained from the study were analysed using descriptive and inferential statistics. At descriptive level, frequency and percentage was used to analyse the bio-data of the respondents while mean and standard deviation was used to answer the research questions. At inferential level, (T-test and ANOVA) were used to analyse the data. Findings from the study among others revealed that; The post-test Academic performance of Agricultural Science Students taught using demonstration method in Senior Secondary Schools in Kaduna State, was significantly higher than the pre-test performance. Similarly the study revealed that there is no significant difference between the academic performance of students taught vegetative propagation in plants using demonstration and discussion methods in senior secondary schools in Kaduna state. The researcher concluded from the findings of the study that, there is significant effect of demonstration method of teaching on academic performance in agricultural science among secondary school students. The researcher also concluded that there is significant differential effect of demonstration, discussion and conventional method on academic performance in digestive system among secondary school students. Recommendations were made to include that Teachers should make use of demonstration method of teaching in senior secondary schools to enhance academic performance of students in Agricultural Science. Preference should not be given to demonstration method of teaching than discussion method in teaching vegetative propagation in secondary schools so as to improve their performances.