The transition through adolescence into adult life is fraught with physical, psychological, and social issues, even for the individual without underlying medical conditions. For the patient with childhood-onset growth hormone deficiency, this transition represents a critical phase, as an increasing body of evidence supports the concept that growth hormone treatment should be continued throughout adult life. Major issues include the need for confirmation of the diagnosis of growth hormone deficiency, the appropriate dosage of growth hormone during the transitional phase, dose titration during treatment, monitoring of therapeutic benefit and potential adverse effects, and optimization of compliance.