To examine the levels of antipolymer antibody (APA) in Korean female patients with fibromyalgia (FM) and to determine whether the levels of APA correlate with FM severity. Serum samples from patients with FM (n = 69), patients with rheumatoid arthritis (RA) (n = 71), and controls (n = 75) were assayed for APA. All of the subjects were female, and the controls were age-matched healthy volunteers. FM tender point counts and scores were examined, and FM patients were asked to complete a Korean version of the Fibromyalgia Impact Questionnaire (FIQ), the State-Trait Anxiety Inventory (STAI), and the Beck Depression Inventory (BDI). APA-positive samples were detected in five (7.2%) of the 69 FM patients, seven (9.9%) of the 71 RA patients, and four (5.3%) of the 75 controls. The prevalence of seropositivity and the level of APA in FM patients did not differ from those in RA patients and controls. The proportion positive for APA was not higher for FM patients with severe symptoms than for FM patients with mild symptoms. There was a negative association between the APA level and age. The APA level in FM patients was not correlated with age at diagnosis, age at symptom onset, disease duration, education, tender point counts and scores, FIQ, STAI, or BDI. The prevalence of APA in Korean FM patients was quite low. Owing to the low prevalence of APA in this study, the APA assay did not distinguish FM patients with severe symptoms from those with mild symptoms.