In this note, we consider a simple duopoly environment in which two parent firms compete in a market. We assume that there are cost differentials between these two parent firms. The parent firms' choices of divisionalization are modeled as a two-stage game. It will be shown that the number of divisions of a parent firm with a cost advantage (i.e., lower marginal costs) is relatively large. The results imply that the cost advantage of one parent firm will be magnified through divisionalization decisions.