One-session treatment (OST), a variant of cognitive-behavioral therapy, combines graduated in vivo exposure, participant modeling, reinforcement, psychoeducation, cognitive challenges, and skills training in an intensive treatment model. Treatment is maximized to one 3-hour session. In this paper, we review the application of OST for specific phobia in youth and highlight practical matters related to OST and its use in a clinical setting. We also briefly review results of treatment outcome studies and suggest future directions for clinical research and practice. We conclude that OST is an efficient and efficacious treatment. (Contains 2 tables.)