OBJECTIVE To assess the frequency and clinical manifestations of osteoarticular brucellosis in an Atlantic area of Spain. METHODS The case histories of all patients older than 14 years of age with active brucellosis diagnosed at the Hospital Xeral-Calde, Lugo, Spain, between October 1979 and October 1997 were reviewed. Diagnosis of brucellosis was by one of the following criteria: isolation of brucella species in blood or other fluids or tissue samples; or a clinical picture compatible with brucellosis in the presence of raised titers of specific antibodies by seroagglutination or Rose-Bengal plate agglutination tests. RESULTS Forty-four patients (34 men, 10 women) of the 158 patients diagnosed with brucellosis (27.8%) had osteoarticular complications. Spondylitis (20/44; 45.5%) and sacroiliitis (15/44; 34.1%) were the most common complications. Patients with spondylitis were older and had a more chronic disease course than those with sacroiliitis or peripheral arthritis. Brucella abortus was the pathogenic strain responsible for human brucellosis in this region of Spain. CONCLUSIONS In the Lugo region of Northwestern Spain osteoarticular brucellosis principally affects males and mainly involves spine and sacroiliac joints.