Generalized normolipemic plane xanthomatosis is a rare cutaneous disorder, frequently associated with reticuloendothelial diseases and some disorders with inflammation. Relapsing polychondritis is also a rare disease that shows an association with various immune-mediated diseases. We report a case of generalized normolipemic plane xanthomatosis associated with relapsing polychondritis in a 56-year-old Japanese man. We have already reported the clinical picture of relapsing polychondritis as well as an increase in urinary glycosaminoglycans excretion in this patient. During subsequent treatment with various immunosuppressive therapy, including prednisone, methotrexate, azathioprine, or aurothiomalate, multiple elevated yellowish erythematous plaques appeared on his neck approximately 32 months after the onset of relapsing polychondritis. Histologically, these eruptions consisted of perivascular neutrophilic infiltrate with nuclear dust and multiple foam cells among collagen bundles, compatible with those of generalized normolipemic plane xanthomatosis. This combination of two rare diseases has not been reported in the literature to our knowledge.