Research shows that cognitive behavioral therapy (CBT) is the most effective approach for treating children and adolescents with post-traumatic stress disorder (PTSD). However, evidence regarding CBT for adolescents with PTSD in Korea is lacking. Written Exposure Therapy (WET), which has the advantages of brevity and tolerability, has important clinical implications as an option for effective treatment of PTSD in the context of the Korean medical system. We aimed to examine the application of WET to adolescents through the cases of four Korean adolescents who underwent WET. The treatment experiences of the four adolescent participants with PTSD are presented, and insights based on their pre- and post-treatment research assessments are discussed. Although evidence is insufficient, our study suggests that WET can be considered a suitable treatment for adolescents who do not have a history of childhood abuse and have a relatively good support system.