This study investigated the effects of advance organizer-based teaching strategy on academic performance of senior secondary schools students in chemistry in Yobe State, Nigeria. The study was guided by two research questions and two null hypotheses formulated and were tested at 0.05 level of significance. The study adopted the quasi-experimental, non-randomized, pre-test, post-test and control group design. The population of the study consisted of 14, 182 students (7,676 males and 6,506 females), who are SS II Chemistry students in Yobe State. The sampled of the study consists of 85 males and 81 females (n = 166) selected from four schools using multi-stage sampling technique. After selection, two schools were randomly assigned to the experimental group and were taught chemistry using advance organizer-based teaching strategy while the other two schools were assigned to control group and were taught chemistry with conventional teaching strategy. The instrument used for data collection was the Chemistry Performance Test (CPT). CPT was subjected to reliability test using K-R 20 and yielded a reliability coefficient of 0.83. Data collected were analyzed using mean, standard deviation to answer research questions while Analysis of Covariance (ANCOVA) was used to test the hypotheses. The findings of the study showed a significant effect of advance organizer-based teaching strategy and conventional teaching strategy on students’ academic performance (F(1, 165)=468.7, P=0.000 ˂0.05).The results showed that gender had no significant effect on academic performance of senior secondary school students when taught using advance organizer-based teaching strategy (F 1, 84 = 1.987, P=0.162 ˃0.05); Based on the findings, the researcher recommended among others that, Chemistry teachers’ should employ the use of advance organizer-based teaching strategy in teaching chemistry because it improved the academic performance of students in Chemistry in Yobe State, Nigeria