Poor pain assessment is cited as one barrier to the adequate treatment of cancer pain. The identification of relevant psychosocial factors may improve the assessment of chronic cancer pain. This article presents: 1) a critical review of the evidence for an association between chronic cancer pain and psychological distress, social support, and coping; 2) clinical implications of the findings; and 3) recommendations for future research. Fourteen of the 19 reviewed studies on psychological distress found a significant association between increased pain and increased distress. Seven of the eight studies on social support found significant association between higher levels of pain and decreased levels of social activities and social support. Three of the four studies that examined coping strategies found that increased catastrophizing was significantly associated with more intense pain. Based on several criteria, the evidence is considered Strong for psychological distress, Moderate for social support, and Inconclusive for coping. This review suggests that comprehensive chronic pain assessment should include routine screening for psychological distress.