This study is concerned with describing the employment history of prisoners. Past labour market performance is a major predictor of later performances. Yet, the substantial field of reentry research paid little attention to pre-prison employment patterns and the magnitudes of labour market disadvantage that prisoners already face prior to their imprisonment. Using data on nearly 2000 Dutch prisoners and a representative sample of the Dutch labour force, we find that underemployment is a longstanding feature of prisoners’ working lives. Starting with a low educational attainment, their subsequent employment career is characterized by long periods of unemployment, “off-the-books” employment, dismissals and job shifts. This results in a marginalized labour market position prior to imprisonment. The findings emphasize that the labour market (re)integration of ex-prisoners is a pressing social and public policy challenge, and stress the importance of skill attainment and work experience among high-risk groups.