Over the past three decades research has highlighted gender differences in substance use disorders and substance abuse treatment participation. Programs devoted to addressing women's treatment needs, broadly encompassed in the term "women-focused treatment," have multiplied. This column examines the rationale for women-focused treatment and describes some of its components. The authors cite the need to evaluate women-focused treatment by developing validated measures of the processes embodied in such treatment and by conducting empirically sound research on clinical outcomes, treatment effectiveness, cost-effectiveness, and the optimal means of providing services to women with substance use disorders.