Achyranthes aspera Linn. (Amaranthaceae) is an abundant indigenous herb in India. It is traditionally being used as an abortifacient. Four successive solvent extracts of the root were screened for antifertility activity in female albino rats. The chloroform and ethanol extracts exhibited 100% anti-implantation activity when given orally at 200 mg/kg body weight. Both the extracts at the dose of 200 mg/kg body weight also exhibited estrogenic activity. Histological studies of the uterus were carried out to confirm this estrogenic activity.