Family physicians continue to struggle with the problem of how to make optimal use of family information in everyday clinical practice. One important task in addressing this problem is describing systematically the categories of family information that are incorporated into the usual clinical problem-solving process used by physicians. In this article the usefulness of the genogram as a data-gathering and assessment tool is reexamined, and six information categories that can be used for generating and testing clinical hypotheses are outlined. Three clinical case studies are presented to demonstrate how physicians can read and interpret genograms systematically.