The association of clubbing with miscellaneous diseases and its diagnostic implications are such that its detection should prompt consideration of the underlying etiology. We encountered a 48-year-old woman with clubbed fingers and a cauliflower-like gingival swelling on the hard palate of the upper jaw. There were no conventionally well-known causes for clubbing. Histological examination of gum biopsy specimen revealed a diagnosis of inflammatory gingival hyperplasia. As an etiology of clubbed fingers, gingivitis was suggested, since clubbing was regressed in parallel with remission of the gingivitis after the treatment by extraction of anterior teeth. Possible involvement of an autoimmune process in the pathogenesis was also considered, because of concomitant elevation of serum anti-double strand DNA antibodies. We recommend examination of the oral cavity for search of an inflammatory disease in cases with clubbed fingers, particularly when other common causes are not apparent.