Ruta graveolens L. is used in many countries, including Brazil, as an abortifacient. To determine its effect on pregnancy, the lyophilized hydroalcoholic extract of its aerial parts was administered orally at a dose of 1000 mg/kg per day to mice between the first and third day of pregnancy (DOP), between the fourth and sixth DOP or between the seventh and ninth DOP. The extract did not cause preimplantation embryonic loss or reabsorptions. Fetal death was found. Estrogenic activity was not exhibited by the extract.