Since the 1930s, research has indicated that unemployment has serious effects on physical and psychological well-being. Recent evidence confirms these findings and provides greater insight into the processes by which unemployment influences health. It is less widely recognised that job insecurity can also adversely affect the health and well-being of workers. This paper reviews the rapidly growing body of research on the health impact of job insecurity and organisational practices that produce insecurity, such as downsizing and restructuring. Our review identified sixty-eight studies, using a variety of methods and measures, published internationally since 1966. Eighty-eight per cent of these studies indicated that job insecurity was associated with diminished worker health and well-being. Implications of this finding for labour market and industrial relations policies, as well as occupational health and safety, are discussed.