INTRODUCTION: This study examines the effects of a Mindfulness-Based Stress Reduction (MBSR) program on psychological measures and attentional patterns to pain stimuli, using eye-tracking methods, in individuals with chronic pain. METHOD: Thirty-two participants with chronic pain and no prior mindfulness experience were randomly assigned to an experimental group or a waiting list group. Both groups completed self-report measures of symptoms, well-being, and an attentional disengagement task using emotional faces as stimuli. Assessments were conducted at two points: before and after the intervention for the experimental group, with the waiting list group serving as a control. RESULTS: Before the MBSR program, chronic pain participants exhibited significant attentional biases towards pain-related stimuli during early attentional stages. Following the program, significant improvements were observed in depression, anxiety, stress, pain acceptance, overall well-being, and life satisfaction. However, it had a limited impact on attentional patterns, with only a significant increase in gaze duration across all stimuli. DISCUSSION: Despite the MBSR program's success in reducing symptoms associated with chronic pain, the lack of broader attentional improvements raises questions about the mechanisms responsible for psychological improvements. SIGNIFICANCE STATEMENT: This study pioneers the use of eye-tracking to examine how MBSR influences attention in chronic back pain. While the program improved psychological well-being, it did not generally alter attentional patterns, except for an increased ability to maintain attention across stimuli. We discuss whether this attentional change could be associated with the increased acceptance observed in the MBSR program.