Twelve consecutive cases of acute chorea occurring among 150.000 pregnant women (1/12.500) are reported. Most of the cases occurred from the fourth do the sixth month of the first pregnancy. The average duration of the symptoms was of three months and no one case of maternal death was verified in the group. The deliveries were spontaneous and normal in all the patients. Only one case of fetal death occurred in consequence of a hemorragic shock. Comments are made on the clinical, laboratorial and prognostic features of chorea gravidarum, being particulary focused the physiopathogenic problem of this condtion.