The conflict in research that exists between the relationship of marital adjustment and sibling constellation is examined here. The belief that the combination of birth order and gender (sibling constellation) is important, is not only a part of folk wisdom but it is a continuing point of view in the literature of marital and family therapy. Data from 250 married subjects were separated into three categories of marital complementarity and relationships and associations were analyzed on the basis of composite scores on the Locke-Wallace Marital Adjustment Test, the number of marriages, and the length of each marriage. The results indicate that the structure of the family of origin has no relationship with current marital adjustment. Across all degrees of complementarity, martial adjustment scores, including happiness, were almost equal. Marital discord, therefore, does not lie in the number and gender of siblings with which one was raised; birth order as a factor in marital adjustment must be eliminated. The findings should form the basis of counselor education courses that focus on counseling couples who show signs of marital discord. (RJM)