Approach and avoidance motivational changes over the course of Emotion Regulation Therapy (ERT) were assessed at pre-, mid-, and post-treatment using an Approach-Avoidance variant of the Implicit Association Test (AAIAT) that specifically targeted implicitly-held action tendencies about approach/avoidance in the context of positively and negatively valenced word stimuli. We expected implicit associations would be demonstrated by reduced AAIAT Total scores from mid- to post-treatment potentially reflecting increased approaching of contexts regardless of valence. We hypothesized that: (1) AAIAT performance would be responsive to ERT during the second half of treatment when the intervention is specifically focused on exposure to approach-avoidance conflict; (2) changes in AAIAT performance during this period would be associated with changes in clinical outcomes; (3) changes in clinical outcomes during the first half of treatment would not be associated with changes in AAIAT performance occurring in the second half. As expected, AAIAT performance significantly changed from mid- to post-treatment, reflecting an increased likelihood of approaching contexts regardless of valence. These changes were related to improvements in quality of life, functional impairment, and negative emotional intensity. ERT shows promise in changing maladaptive approach/avoidance motivational tendencies for individuals with distress disorders, particularly during the second half, when treatment is focused on approach-avoidance content. This study underscores the value of implementing behavioral tasks as complementary tools to self-report measures in furthering our understanding of core mechanisms (e.g., motivation) implicated in the psychopathology and treatment of distress disorders.