This issue on sex and gender comes at an opportune time, as the DSM-IV is being revised, and in particular sex and gender issues are being reconsidered. This issue focuses on research in the area of gender variant children and transgender adolescents, assessment of several scenarios and clear information on practice parameters. Therapy for gender variant children and transgender adolescents is discussed in detail, as well as parents' perspectives, ethical legal, and non-discrimination issues, and education on these subjects. International standards of care are also discussed.