This prospective longitudinal study examined treatment outcomes among 1,073 methamphetamine-abusing patients (567 women, 506 men) from 32 community-based outpatient and residential programs in 13 California counties. Data were collected at intake and at 3 months and 9 months after admission. With one exception, improvements from baseline to follow-up were observed in all areas measured by the Addiction Severity Index for both women and men in either modality. Compared to men, women demonstrated greater improvement in family relationships and medical problems, and similar improvement in all other areas, despite the fact that more women were unemployed, had childcare responsibilities, were living with someone who also used alcohol or drugs, had been physically or sexually abused, and reported more psychiatric symptoms. Implications for service improvement are discussed.