ABSTRACT: BACKGROUND:Cognitive behavioral therapy (CBT) for young people is increasingly being provided using technology-assisted formats. Although there is increasing evidence regarding the efficacy of such approaches, as illustrated by quantitative systematic reviews, the literature has also highlighted challenges with implementation factors, including high attrition rates and variable user engagement. Qualitative review methods can help to address the factors that impact young peoples' experience of technology-assisted cognitive behavioral therapy (tech-assisted CBT) and, thus, enable us to better understand such implementation factors. To date, no such qualitative synthesis exists. OBJECTIVE:The primary aim of this review was to systematically identify and synthesize the qualitative literature concerning the experiences of young people who have used tech-assisted CBT. METHODS:This systematic review applied Thomas and Harden's 2008 qualitative thematic synthesis approach. This involved line-by-line coding of the results sections of included studies and an inductive analysis on identified themes, followed by the generation of analytical themes through a process of iteration and interpretation of the descriptive themes. PsycINFO, ACM Digital Library, PubMed, EMBASE, and JMIR Publications databases were searched. The inclusion criteria were (1) studies involving school-aged young people over preschool age (6 years) but under the age of 18 years, (2) use of any form of tech-assisted CBT for any time period, (3) a stated focus of qualitative data to document the experiences of participants, and (4) studies published in English. The exclusion criteria were (1) interventions only provided face-to-face with no technological component, (2) only focused on the performance of the technology rather than participant experience, and (3) numerical data that sought to represent qualitative data. RESULTS:A total of 14 studies were included in this review. Overall, these studies represented interventions for low mood and anxiety (n=10), trauma or self-harm (n=2), and physical difficulties (n=2). Overall, 5 analytical themes emerged on young people's experiences with tech-assisted CBT: (1) helpfulness, (2) therapeutic process, (3) transferability, (4) gameplay experience, and (5) limitations. In addition, these analytical themes contained the following subthemes: positive experiences, tech-assisted CBT versus face-to-face CBT, understanding of a CBT model, process of change, skills development, application to everyday life settings, parental involvement, character relatedness, playability, negative experiences, and broad content. CONCLUSIONS:Overall, young people's experiences with tech-assisted CBT were mostly positive. The use of gaming environments, relatable characters, concrete metaphors, and age-appropriate narratives contributed to these positive experiences. Evidence suggests that technology can help to mediate face-to-face relationships with therapists and help young people to understand the CBT model. Clear barriers also emerged, including over-reliance on reading and writing skills and dissatisfaction with overly generalized content and comparison with commercial technologies. TRIAL REGISTRATION:International Prospective Register of Systematic Reviews (PROSPERO) CRD42018103388; https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42018103388.