To evaluate the efficacy and complications of dilatation and curettage (D&C) and vacuum aspiration (VA), pertinent data on 4,463 patients at seven to 19 weeks' gestation undergoing artificial abortion were analyzed. Before nine weeks' gestation VA appears to be safer than D&C, but after 12 weeks' gestation VA is associated with higher rates of uterine injury and excessive blood loss. At nine to 12 weeks' gestation there is little difference in the over-all complication rates of the two procedures. Data on 614 patients undergoing suction curettage within two weeks of a missed menstrual period (a time when pregnancy cannot be reliably diagnosed) were analyzed. The morbidity was lower in this group than in any group undergoing abortion. Thus, the earlier the abortion is performed the lower the morbidity. The need for secondary procedures, anesthesia, or cervical dilatation is infrequent for early VA when compared to abortion by D&C and VA at later stages of gestation.