The aim of this study was to determine the neonatal outcome in women with well-characterized antiphospholipid syndrome treated during pregnancy with low-dose aspirin. We compared 38 babies born after 36 pregnancies of 33 women diagnosed as having antiphospholipid syndrome with a group of 38 control infants matched for the same gestational age at birth. In all 76 newborns we studied the maternal events associated with the antiphospholipid syndrome, mothers' treatment and neonatal data. All mothers with antiphospholipid syndrome were treated with low-dense aspirin. Prednisone was only prescribed due to maternal complications and heparin in a case of thrombosis. No significant relation was found between maternal treatment and neonatal complications. The prematurity rate in these newborns was high 14% and the neonatal mortality (5.8%) was only associated with extreme prematurity (p < 0.001). In our population the overall rate of neonatal complications was higher than in the general population, but when compared with a similar group of newborns no significant differences were found. Our results suggest that primary antiphospholipid syndrome appears to be improved by low-dose aspirin treatment, with a high rate of neonatal survival (95%). Except for prematurity and its potential associated complications, fetal and neonatal outcome is very favourable and no significant relation between maternal treatment and neonatal pathology has been detected.