Neurological complications of systemic lupus erythematosus (SLE) are relatively common, but chorea as the initial manifestation of SLE unmasked by exogenous estrogen is very rare. A-46-year old right handed woman presented with generalized chorea since 2 weeks ago. Her medical records revealed that the chorea had appeared within one month after estrogen medication. The laboratory test revealed positive antinuclear antibody (ANA), positive anti-dsDNA and positive anti-histone antibody. After discontinuation of estrogen, her choreic movement was not diminished. We report a case of newly diagnosed SLE attribute to chorea which triggered by estrogen.