The recent decline in Coronary Heart Disease (CHD) mortality rates has been attributed to reduction in risk factors and to improved management. In this article, we review whether artefacts of classification could have played a role as well. Knowledge and information on disease, competing causes of death, death certification accuracy and completeness, advancing age of the population with multiple conditions as well as death certificate coding practice could have affected secular trends of CHD mortality rates. However, the lack of noticeable shifts within the cardiovascular category or with another category makes it difficult for the CHD decline to be artefactual.