Teacher knowledge has been regarded as important tool for improving students’ academic performance. Thus, the knowledge gained by teachers would transform teaching activities in the classroom. It is imperative for Nigeria teachers to keep abreast of latest information that would help teaching and learning in Nigeria secondary schools. Therefore, this study examined structural equation modeling to determine the relationship between teacher knowledge and students’ academic performance with mediating effect of teacher commitment. A quantitative research approach was used to determine the relationship among the three variables. Four hundred (400) teachers were selected through stratified random sampling technique. Structural equal modeling (SEM) analysis was employed to test the data fitness in with constructs formulated in the model. Based on the findings of the study, there was direct and significant relationship between teacher knowledge and students and academic performance. Also, teacher commitment was able to mediate on the relationship between teacher knowledge and students’ academic performance. The findings encourage the schools to up-date their teachers by given them in-service training.