To assess the validity of death certificate diagnoses of out-of-hospital coronary heart disease deaths, the authors studied a one-third random sample of out-of-hospital deaths occurring in 1979 in Minneapolis-St Paul, Minnesota, residents. Death certificates with diagnoses possibly containing coronary heart disease deaths were enumerated, and cause of death was recorded from the certificate in two ways: 1) as the first listed (“immediate”) cause and 2) as the “underlying cause” assigned by a trained nosologist. Validation was performed by standardized physician review of information obtained about the death, which included one or more of the following: an interview with a relative or friend, physician report, autopsy report, medical record, and/or nursing home record. Missing information was frequent, but cases with at least an informant interview and/or autopsy report (82%) were representative and could be used for validation. The sensitivity and specificity of the underlying cause of coronary heart disease (International Classification of Diseases, Ninth Revision, codes 410–414, 427) on the death certificate were 90.3% and 82.7%, respectively, compared with the physician-assigned diagnosis. For the immediate cause, sensitivity and specificity were 90.3% and 67.9%, respectively. These findings suggest that the validity of death certificates for out-of-hospital coronary heart disease death is high, as assessed by this method of retrospective physician review.