Although prior research has discussed the relationship between subsidiary performance and headquarters-subsidiary relationships in MNCs, few studies have focused on the relationship between subsidiary performance and subsidiary-subsidiary relationships, especially internal competition among subsidiaries in MNCs. Therefore, this article investigates the relationship between subsidiary performance and levels of internal competition among subsidiaries and the conditions under which levels of internal competition have a positive association with subsidiary performance. This study conducted logistic regression analysis based on a questionnaire survey of 269 Japanese manufacturing subsidiaries in Southeast Asia. As a result, we show that levels of internal competition among subsidiaries are positively associated with subsidiary performance only when the subsidiaries are acquired subsidiaries.