This paper examines the corporate parent effect on the diversification strategies of triad and Asian subsidiaries in the ASEAN region. I find that triad subsidiaries tend to participate in high technology intensive industries, and are more likely to diversify. In addition, I also find that the subsidiary diversification strategy is significantly affected by the number of affiliations under the same corporate parent that perform the same or different activities in the region. These results shed light on the influence of corporate parent on subsidiary-level strategy and the role of the subsidiary within an economically integrated region. Various implications are discussed.