The comorbidity between chronic pain and emotional problems has proven difficult to address with current treatment options. This study addresses the efficacy of a transdiagnostic emotion focused exposure treatment ("hybrid") for chronic pain patients with comorbid emotional problems. Adults (n=115) with chronic musculoskeletal pain, functional and emotional problems were included in a two centre, parallel randomized controlled, open label trial comparing this treatment to an active control condition receiving a guided internet delivered pain management treatment based on CBT principles (iCBT). The hybrid treatment (n=58, 10-16 sessions) integrates exposure in vivo for chronic pain based on the fear-avoidance model with an emotion regulation approach informed by procedures in Dialectical Behavior Therapy. The iCBT (n=57; 8 treatment modules) addresses topics such as pain education, coping strategies, relaxation, problem solving, stress and sleep management using standard CBT techniques. Patient-reported outcomes were assessed pre- and posttreatment as well as at a 9-month primary end point. Across conditions, 78% participants completed post-treatment and 81% follow-up assessment. Intent-to-treat analyses showed that the hybrid had a significantly better post-treatment outcome on pain catastrophizing (d=0.39) and pain interference (d=0.63) and significantly better follow-up outcomes on depression (d=0.43) and pain interference (d=0.51). There were no differences on anxiety and pain intensity. Observed proportions of clinically significant improvement favoured the hybrid on all but one comparison, but no statistically significant differences were observed. We conclude that the hybrid emotion focused treatment may be considered an acceptable, credible and efficacious treatment option for chronic pain patients with comorbid emotional problems.This is an open-access article distributed under the terms of the Creative Commons Attribution-Non Commercial-No Derivatives License 4.0 (CCBY-NC-ND), where it is permissible to download and share the work provided it is properly cited. The work cannot be changed in any way or used commercially without permission from the journal.