A sample of 1776 adult women in treatment for chemical dependency was divided into two age groups: 30 or under and over 30. The two groups were compared for substance use histories and other psychosocial variables. Significant differences emerged in the use of illicit drugs, social use patterns and familial histories. Findings suggest that differences may be related to generational as well as age effects. The study highlights the heterogeneity of women in treatment and emphasizes the need to assess and respond to women''s chemical dependency in the context of sociocultural transitions.