Community service, along with other new sanctions, has been recommended in many Western countries as an alternative to incarceration over many years. Despite a rich literature on evaluations of alternative sanctions, random assignment has only exceptionally been used in this field, and short-term imprisonment has never been an option in such designs. This study attempted to assess the comparative effects of community service and prison sentences of up to 14 days, through a controlled experiment in Switzerland in which 123 convicts were randomly assigned. There were no differences with respect to later employment history and social and private life circumstances. However, re-arrest by the police was more frequent among those randomly assigned to prison than among those selected for community service. Prisoners also developed more unfavorable attitudes towards their sentence and towards the criminal justice system. Tables, figure, notes, references