Recent literature has suggested that the traditional dichotomy of organic vs. functional classification for pain patients is unimportant in determining the role of personality variables in predicting treatment outcome. The present study examined the role of MMPI variables in predicting treatment outcome in pain patients with definitive physical disorders (N = 58) (organic) and in patients without definitive physical findings (N = 46) (functional). In the organic group, the presence of high Hs was associated with poor outcome, while in the functional group K scores were associated with poor outcome. Results suggested that although personality variables played an equal role in both groups, the nature of that contribution may vary in the functional and organic groups.