This article analyzes the effects of employment on delinquent development from 18 to 32 years of age in 270 high-risk males. Prior to 18 years of age, all men had undergone residential treatment for serious problem behavior in a juvenile justice institution in the Netherlands. We use semiparametric group-based models to investigate the effect of employment on their offending, taking into account static personality and background characteristics. We examine the effect of being employed and further distinguish the effects of job quality ("on the payroll" or being employed through temporary work agencies) and job stability (duration). We find that employment is significantly related to delinquent development among most (active) offender groups. Among high-frequency chronic offenders, only temporary employment is significantly associated with a reduction in offending, whereas among high-frequency desisters, the association is significantly stronger with regular employment. Stability in employment was limited in our sample, and it did not have an additional effect on offending. © 2011 American Society of Criminology.