Several studies suggest that religious involvement or spiritual well-being may affect health outcomes. This study was designed to investigate whether the scores from a questionnaire measuring spiritual well-being correlated with progression or regression of coronary heart disease as measured with computerized cardiac catheterization data. Participants in Dr Dean Ornish's Lifestyle Heart Trial were given the "Spiritual Orientation Inventory." A significant difference was found in the spirituality scores between a control group and a research group that practiced daily meditation. The spirituality scores were significantly correlated with the degree of progression or regression of coronary artery obstruction over a 4-year time period. The lowest scores of spiritual well-being had the most progression of coronary obstruction and the highest scores had the most regression. This study suggests that the degree of spiritual well-being may be an important factor in the development of coronary artery disease.