This study investigates the roles of the regulative, normative, and cognitive institutional pillars as perceived obstacles and facilitators of internationalization within an integrated region. Integrated regions involve efforts to create institutional similarities among member nations and encourage intra-regional trade. These efforts make integrated regions a theoretically interesting and important context for analyzing managerial perceptions of the institutional environment. We content analyze essays and questionnaires from managers in the East African Community (EAC) to compare the three pillars. Our findings suggest that managers perceive the regulative pillar to be the greatest source of institutional obstacles to expansion within the EAC. Interestingly, the managers also perceive the regulative pillar to be the greatest source of institutional facilitators of expansion within the EAC.