Chorea was observed in a 12-year-old girl with primary antiphospholipid syndrome (APS). She developed severe chorea in a few weeks. On immunosuppressive treatment, including high doses of glucocorticoids and cyclophosphamide, she had a rapid clinical recovery. Single photon emission computed tomography (SPECT) of the brain showed decreased circulation in the basal ganglia and in the medial parts of both temporal lobes. One month after treatment, SPECT was completely normalised. APS in children has a variety of clinical manifestations, and should be suspected in cases of unexplained thromboembolic disease or obscure neurological symptoms.