A short-form of the McGill Pain Questionnaire (SF-MPQ) has been translated into Swedish. One hundred women with either fibromyalgia (FS) or rheumatoid arthritis (RA) filled out the SF-MPQ three times--the RA patients monthly while receiving their routine care, and the FS patients over 6 months while participating in an experimental treatment. Results indicated that the MPQ 15-item descriptor section was internally consistent (Cronbach's alphas .73 to .89), but lacked content validity in the RA sample. Test-retest reliabilities ranged from .45 to .73. Convergent construct validity was demonstrated by significant correlations between the SF-MPQ and other pain measurements. A principal components analysis showed that the 15-item descriptor section has three distinct factors: acute sensory, chronic sensory, and affective. We conclude that the SF-MPQ is reliable and valid for use with FS patients.