As many as two-thirds of newly-released inmates will be arrested for a new offense within three years. This study evaluates the impact of job assistance on recidivism rates among ex-offenders. The job assistance program, run though the private company America Works, uses a network of employers to place clients. Ex-offenders were randomly assigned to intensive job assistance (treatment group) or the standard program (control group). The intensive program is meant to improve average work readiness for ex-offenders. It reduces the likelihood of subsequent arrest among non-violent ex-offenders, but has little effect on violent ex-offenders. The re-arrest rate for non-violent ex-offenders in the treatment group was 19 percentage points lower than those in the control group. The re-arrest rate for violent ex-offenders in the treatment group was indistinguishable from those in the control group. We estimate benefits from intensive job assistance from averted crimes and find that they outweigh the $5,000 up-front cost for non-violent ex-offenders.