A case of Churg-Strauss syndrome complicated by chronic symmetrical dacryoadenitis suggestive of Mikulicz's disease is herein presented. A 72-year-old Japanese man, who had been previously diagnosed with asthma, presented with weakness of the left leg and purpura on the lower extremities. A neurological examination showed multiple mononeuropathies and a laboratory examination revealed elevated eosinophil counts, IgE levels and the presence of Myeloperoxidase-antineutrophil cytoplasmic antibody (MPO-ANCAs). Churg-Strauss syndrome was diagnosed, although the patient also exhibited bilateral swelling of the lachrymal glands. Furthermore, elevated serum IgG4 levels, an infiltration of a relatively large number of IgG4-positive plasmacytes in the nasal mucosa and hypocomplementemia were also observed. These findings were consistent with a diagnosis of Mikulicz's disease (MD). Oral prednisolone (30 mg) was administered and the swelling of the lachrymal glands resolved. Churg-Strauss syndrome may be accompanied by Mikulicz's disease (an IgG4-related disease), and common pathogeneses between Churg-Strauss syndrome and IgG4-related disease may exist.