Several studies, mainly from the U.S. and usually with selected male samples, show that aftercare is positively related to lower risk of re-addiction or re-treatment. The present study extends this line of research in a report from public health health care addiction treatment services in Stockholm County. The study sample comprises all 196 men and 100 women alcohol-dependent patients from 10 districts hospitalized for at least 2 days during 1997-99 and who received outpatient care within 5 days. These patients were followed up until 2000, without attrition for renewed rehospitalization. Greater length of outpatient treatment was significantly related to reduced rehospitalization, but only in men. The intensity (average number of visits) of outpatient treatment was not significantly related to rehospitalization. The different effect of length of outpatient treatment between the genders may be due to differences in severity of alcohol dependence, social situation, psychiatric co-morbidity, and/or the extent to which treatment met patients' needs.