Аннотация:Meeting the needs of women manifesting substance-use disorders is a goal in developing treatment programs for this population. As retention in treatment is positively related to treatment outcome, the length of stay in outpatient treatment of alcohol- and other drug-dependent women in Brazil was compared between two programs. Data were analyzed from 181 women entering a Mixed-Gender Program from 1986 to 1996 and from 80 women entering a Women-Only Program from 1997 to 1998. A greater 3-month retention rate was observed in the Women-Only as opposed to the Mixed-Gender Program. Moreover, the impact was more significant among the alcohol-dependent women. This finding suggests that the heterogeneity of women with substance-use disorders has to be taken into account when developing appropriate treatment strategies.