In 1982 Massachusetts mandated that individuals convicted of a second drunk driving offense either be committed for at least 7 days in a house of correction or enter a 14-day residential alcoholism treatment program for second offenders. The followup study compared data on 199 individuals admitted to the 14-day program at the Rutland State Hospital and 190 individuals incarcerated for a drunk driving offense between January and May 1983. Followup data were obtained during June and July 1985 for the Rutland sample and during July and September 1985 for the incarcerated offenders. The incarcerated sample was slightly younger, had more prior drunk driving charges, and showed greater criminality than those who entered treatment. Offenders admitted to the treatment program were significantly less likely to be rearrested for drunk driving. Ten percent of the treatment sample and 20 percent of the incarcerated sample were rearrested. A summary odds ratio suggested that when adjusted for differences in prior arrests, the risk of rearrest was 1.9 times greater among incarcerated offenders. Tables and 10 references. (Author abstract modified)