The gathering of family information has numerous advantages in a family practice setting. Methods are described which not only allow description of family structure but permit identification of each individual family member and his/her relationship to the family as a unit. The value of filing individual medical records in family folders is detailed. A functional definition of family is established and certain health-related characteristics are given. Included is comparison of family size and socioeconomic status (SES) of a family practice with census information on the total county population. Health-seeking behavior of two-person families (couples or single-parent plus child) related to SES is presented as one of many applications of recorded family information, potential for future research into the effects of family structure on morbidity is discussed.