A 60-year-old man was admitted to our hospital because of heat intolerance induced by generalized anhidrosis. There were no abnormal findings on physical and neurological examinations except for anhidrosis. Reflex sweating to pilocarpine and acetylcholine was absent. Skin biopsy revealed no abnormalities of the sweat glands and ducts. Laboratory tests showed elevated levels of serum IgG and rheumatoid factor. Anti-nuclear antibodies, and antibodies to Sjögren's syndrome A and B were positive. Ocular examination revealed the presence of keratoconjunctivitis sicca. The pathological findings of minor salivary gland specimen confirmed a diagnosis of Sjögren's syndrome. This case suggests that generalized anhidrosis could be caused by the antigen-antibody reaction for the cholinergic receptor of sweat gland.