There is limited understanding of attrition (premature treatment withdrawal and non-completion) from pediatric chronic pain services. This narrative review aimed to summarize attrition prevalence from face-to-face pediatric outpatient chronic pain interventions, identify associated factors and develop a theoretical model to account for attrition in this setting. A comprehensive search of the published literature revealed massive variability (0–100%) in the reported attrition rates from pediatric chronic pain interventions that varied in type and format (individual vs. group, single discipline vs. interdisciplinary, psychological only vs. multiple combined interventions, of different durations). The factors associated with attrition from pediatric chronic pain programs varied between the studies: some have assessed patient sex, psychological and other comorbidities, avoidance strategies, missed schooling, family composition/tensions, caregiver catastrophizing, scheduling, caregiver leave and clinic access. A theoretical model is presented depicting youth, caregiver and service factors that may impact attrition from pediatric chronic pain interventions. Where available, literature is drawn from the pediatric chronic pain context, but also from adult chronic pain and pediatric weight management fields. The implications for research and clinical practice are discussed, including improved reporting, patient screening and targeted supports to promote intervention completion. This review contributes to a better understanding of attrition, which is crucial for optimizing pediatric chronic pain service outcomes.