A 51-year-old Negro woman had a fiveweek history of unilateral proptosis. Multidimensional medical evaluation eliminated endocrine, infectious, and neoplastic disorders. The patient had a ten-year history of discoid lupus erythematosus (LE), positive immunofluorescent band tests, and a histopathological report that a hematoxylin-eosin-stained section of the lid skin was "consistent with LE." Four months later, a positive antinuclear antibody test confirmed the diagnosis and suggested its progression from discoid to systemic LE. Orally administered prednisone had a dramatic curative effect on the ocular condition. Proptosis appears to be a manifestation of other collagen diseases, and led us to conclude that LE was the cause in this case. Proptosis has not previously been reported as a manifestation of LE.