Education is taking the main priority of any country nowadays and teachers hold an important role in improving human resources. Teachers’ performance is reflected by one of its dimensions called organizational citizenship behavior (OCB) used as the most measurable indicator in evaluating teachers. That was why it was urgent to study whether teachers, in this case, biological teachers’ OCB hypothesized affected directly or indirectly by teachers’ leadership (TL) and their integrity (IN). Therefore, a causal survey was used by selecting randomly 97 senior high school biological teachers, in the district of Cilegon, West Java, Indonesia. There were three instruments developed to measure teachers’ OCB (reliability was 0.947), TL (reliability was 0.947), and IN (reliability was 0.926). Data were analyzed by path analysis. The research results revealed that TL affected teachers’ OCB, but its effect was not significant. However, IN directly and significantly affected teachers’ OCB, and TL directly and significantly affected teachers’ IN as well. Its indirect effect was also found not significantly affected teachers' OCB by teachers’ TL through teachers’ IN. Based on these findings, it was also found that IN was not a good mediated factor as did confirm what was depicted by Colquit, et.al. (2019) model of integration in organizational behavior. Needless to say, it could be concluded that if schools or any other institutions plan to improve teachers ’performance (OCB), by minimizing its OCB variation, therefore, some school policies should consider only the stronger teachers’ integrity through the training packages. Keyword : Organizational citizenship behavior (OCB), teacher leadership, path analysis, and reliability (rel.)