The aim of this longitudinal multisite randomized controlled trial (RCT) was to evaluate the effectiveness of the EMDR-Integrative Group Treatment Protocol for Ongoing Traumatic Stress (EMDR-IGTP-OTS) in reducing severe posttraumatic stress disorder, depression, and anxiety symptoms in refugee minors living in Valencia, Spain. The study was conducted in 2019 in the city of Valencia, Spain, in six sites for refugees (homes or residences). A total of 184 minors (all males) met the inclusion criteria. Participants' ages ranged from 13 to 17 years old (M =16.36 years). Participants' time since the arrival to the sites in Valencia varied from January 2018 to March 2019. Participation was voluntary with the participants and their legal guardian's consent. In this study, intensive EMDR therapy was provided. This intensive format allowed the participants to complete the full course of treatment in a short period. Treatment was provided simultaneously by eighteen licensed EMDR clinicians formally trained in the protocol administration divided into six teams. Each of the treatment group participants received an average of eight hours of treatment, provided during nine group-treatment sessions, three times daily during three consecutive days in a setting inside the six refugee sites. EMDR-IGTP-OTS treatment focused only on the distressing memories related to their life as refugees and did not address any other memories. No adverse effects were reported during treatment or at three-month post-treatment assessment. Data analysis by repeated measures ANOVA showed that the EMDR-IGTP-OTS was effective in reducing PTSD symptoms in the treatment group (F (2, 122) = 43.17p <.001, η P 2 =.414). A significant effect for group (F (1, 61 = 5.52, p<.05, η P 2 =.898) and a significant interaction between time and group for this variable, (F (2, 122) = 11.10, p <.001, η P 2 =.154) confirmed the effects of the treatment. Significant effects for time (F (1, 61) = 7.46, p <.001, η P 2 =.109) and for interaction between time and group (F (1, 61) = 6.13, p <.01, η P 2 =.091) were found for both, anxiety and depression, (F (1, 61) = 7.02, p <. 01, η P 2 =.104) and (F (1, 61) = 7.92, p <.001, η P 2 =.116). The study results indicate that the intensive administration of the EMDR-IGTP-OTS could be a feasible, cost-effective, time-efficient, culturally sensitive, and effective component of a multidisciplinary psycho-social group-based program to address PTSD, depression, and anxiety symptoms among refugee minors.