A method is presented for adjusting the scheduling of appointments in ambulatory health care centers to reduce the deleterious effects of broken appointments. The essence of the methodology calls for scheduling and "expected number" of patients for a given clinic session. This "expected number" is calculated from estimated probabilities of appointment breaking, conditioned on patient characteristics which are deemed to be related to appointment-breaking rates, and on which number appointment within a specified time period is being made for the patient. The two ill effects of appointment breaking that are considered here are the diminution of efficiency of operation and interference with continuity of patient care. Ways of using this methodology to ameliorate each of these effects are outlined, with one of these way serving to alleviate both effects. This method is meant to be of quite general applicability, although its development was motivated by the problems of a localized particular situation.