OBJECTIVE: To develop and implement a computerized version of the International Classification of Primary Care. To create a data bank and to conduct a descriptive study of our clinic's clientele. DESIGN: Testing a software program and creating a data bank. SETTING: Family Medicine Unit at Enfant-Jésus Hospital, Quebec City. PARTICIPANTS: All Family Medicine Unit doctors and patients seen between July 1, 1990, and June 30, 1993. MAIN OUTCOME MEASURE: Description of our clientele's health problems using the ICPC. RESULTS: During the study, 48,415 diagnostic codes for 33,033 visits were entered into the bank. For close to 50% of these visits, two or more health problems were coded. There was good correlation between the description of our clientele and descriptions in other studies in the literature. CONCLUSION: This article describes the development of a data bank in a family medicine unit using a software program based on the ICPC. Our 3-year experiment demonstrated that the method works well in family physicians' daily practice. A descriptive study of our clientele is presented, as well as a few examples of the many applications of such a data bank.