The influences of the psychosocial work environment on incident coronary heart disease and diabetes and the influences of change in work risk factors on health are reported from the longitudinal Whitehall II cohort study of 10308 British Civil Servants. The contribution of alcohol consumption and alcohol dependence to absence from work attributable to accidents is also investigated. High job demands, low decision latitude and effort reward imbalance were related to increased incidence of coronary heart disease. Work characteristics were not associated with the incidence of diabetes, with the exception of effort reward imbalance which was related to increased incidence of diabetes in men. These effects were not explained by conventional risk factors such as smoking and blood pressure. Adverse changes in levels of work characteristics, particularly social support at work, predicted worsening mental health functioning in men and women. The effects of change in work characteristics on physical health and coronary heart disease were modest, although there was some evidence to support a longer term influence on physical functioning and longstanding illness. Alcohol consumption was related to risk of sickness absence due to injury with increased risk seen at moderate levels of alcohol consumption. "Binge" drinking and alcohol dependence were also related to absence due to injury.