To investigate how acceptance of illness affects chronic pain in terms of attention towards pain and fearful thinking of pain. 62 participants (50 women) with chronic pain carried a palmtop computer for 2 weeks. Eight times each day auditory signals were delivered to cue participants to complete questions about their experience. Multilevel analyses indicated that on moments with more intense pain, more fearful thinking about pain, and less positive emotions, attention to pain was increased. Illness acceptance did not moderate the relation between pain intensity and attention to pain. Results further indicated that on moments with more intense pain, more negative emotions, and less positive emotions, fearful thinking about pain was increased. Of particular interest was the finding that the relationship between pain intensity and fearful thinking about pain was less strong for those high in acceptance. Pain captures attention and elicits fearful thinking about pain. Acceptance may be a useful avenue to lower negative thinking about pain, and to increase well-being in patients with chronic illnesses.