ObjectiveTo investigate the relationship between mycoplasma pneumonia infection (MP) and acute urticaria (AU). MethodsFrom December 2011 to November 2012, in the department of clinical laboratory of the Lishui Central Hospital, the blood samples of 178 patients with acute urticaria (group AU) and 200 healthy volunteers (group C) who initially visited this hospital were collected to detect the MP-IgM+IgG+IgA antibody in the serum. The occurrence of positive MP antibody was recorded and the positive rate was calculated. ResultsCompared with group C, the incidence of positive MP was significantly increased in group AU (P < 0.01). ConclusionMycoplasma pneumoniae infection may be one of the causes of acute urticaria.