Community surveillance was conducted to allow the calculation of comparable, city-specific rates for total mortality, cardiovascular mortality, fatal myocardial infarction, nonfatal myocardial infarction, fatal and nonfatal stroke. Development of the community surveillance system was done in close collaboration with the Minnesota Heart Health Project and the Pawtucket Heart Health Project to insure comparability. Only those cardiovascular disease events which always resulted in hospitalization were monitored and included myocardial infarction and stroke. Fatal cases were identified from county death certificate files. Both fatal and nonfatal hospitalized events were investigated by abstracting the medical records onto a set of standard forms. All non-hospitalized deaths were investigated by contacting the decedent's family for medical history and circumstances of death and by contacting the decedent's physician for medical information. Data were monitored on the severity of coronary events and on the quality of care. An Acute Coronary Care form was designed in cooperation with the Minnesota surveillance project and with the MONICA project. The form was field tested in September 1985 and was implemented retroactively on 1980 and 1981 cases.