This is one of the few cross-cultural studies of division of household work using American and Japanese samples. Tested is a theoretical model based on time, availability, resource exchange, and gender stratification perspectives regarding how much household work each spouse performs. It is found that household work is shared more equally in American couples, and this difference is not ar-counted for by different levels in predictor variables between the two samples, suggesting structural differences in these two countries. Also found is a more rigid allocation of household work among Japanese couples and weaker explanatory power of the model for them. Although the theoretical model applies weakly to Japanese couples, the article questions the relevance of the model proposed and tested in the United States for families in other societies.