This study investigated the effects of information system (IS) integration on financial performance in Tehran Stock Exchange with an emphasis on the mediating role of cost performance and quality performance. This survey was carried out in 2018 by distributing 300 questionnaires among all CEOs, financial administrative vice-presidents, accounting managers, and accountants of manufacturing companies listedin the Tehran Stock Exchange. A total of 250 questionnaires were returned, and the data were analyzed in SmartPLS using structural equation modeling (SEM).The results confirmed the significant positive relationships of flexibility, completeness, and knowledge sharing with IS integration. In addition, IS integration affected corporate financial performance both directly and through the mediating variables of cost performance and quality performance. In other words, any increase in each of these three variables led to an improvement in corporate financial performance. Manuscript profile