--- - |2+ Abstract Background The present study evaluated the influence of psychological factors (anxiety, depression, fear avoidance, and self‐efficacy) in predicting patient adherence to their personalised post‐intervention treatment maintenance plan for the interval between discharge from an out‐patient treatment and follow‐up at 3–6 months. Methods Participants included 61 chronic pain patients aged 31–72 years (M = 54.28, SD = 10.32) who had completed a pain management program between 2014 and 2016 at a rehabilitation centre. Participants completed measures of the psychological factors at pre‐intervention and at the completion of the program; and a measure of treatment maintenance adherence at 3–6 months post‐intervention to measure compliance with the post‐discharge treatment plan. The psychological factors at both timepoints were included in regression models to determine whether pre‐ or post‐intervention scores predict adherence, and whether these effects are dependent on how much these psychological factors change during the intervention phase. Results Hierarchical regression analyses showed that 28% variance in post‐intervention adherence to post‐intervention treatment maintenance plans was accounted for by the predictors. Fear avoidance and depressive symptoms (both at post‐intervention) made significant unique contributions to prediction. Moderation analyses showed that individuals with initially low levels of anxiety, whose symptoms worsened during the intervention phase, were more likely to adhere to the post‐discharge treatment plan. Conclusions This pattern of findings shows relevance for psychological factors in treatment adherence. Nevertheless, questions remain about the nature of their influence on adherence, and clinical and research implications are discussed in this light. - Clinical Psychologist, EarlyView.