The genogram is presented as a technique to record both genetic and interpersonal family-household data. Working with model patients, and using standard instructions and symbols, family medicine residents elicited and recorded an average of 83 percent of available information items during interviews that lasted an average of 16 minutes. Interpretation of data derived from genograms written by other physicians was achieved with a high degree of accuracy (91 to 96 percent correct answers to 25 questions on each of three family-households). The genogram appears to be a practical instrument to record and retrieve family-household data, but its wide application will require standardization of both the technique of recording and the symbols employed.