The relationship between length of unemployment and psychological ill-health was examined in a sample of 954 unemployed working-class men, selected to cover all levels of age and several levels of duration of unemployment. The association between length of unemployment and psychological ill-health was found to be strongest in the middle age groups, with greater ill-health among those with a longer duration since job loss. No association between duration and ill-health was found for those who had recently entered the labour market or who were close to the end of their working lives. Desire for a job and financial stress were shown to be additional mediators of psychological ill-health during employment. A cumulative stress model is proposed to account for these findings.