The purpose of this study was to determine the association of fibromyalgia (FM) with temporomandibular disorder (TMD) and masticatory myofascial pain (MMP). Thirty-one consecutive women diagnosed as having FM according to American College of Rheumatology criteria and 21 consecutive women diagnosed as having TMD were included in this prospective study. All patients were examined by a dentist and a physiatrist to identify the coexistence of FM and TMD. In the FM group, TMD was found in 25 (80%) patients, and only 6 (19%) patients had arthrogenous origin with MMP, whereas 19 (81%) patients had only MMP without arthrogeonous orgin of those 25 women exhibited TMD. In the TMD group, the prevalence of FM was 52%, which was significantly higher in those with TMD of arthrogenous origin with MMP. Our results indicate that coexistence of FM and TMD with MMP is high. Pain and tenderness in the masticatory muscles appear to be an important element in FM, so in some patients it may be the leading complaint.