['Cervical carcinoma is the second most common malignancy in females and most of the cases are found in developing countries. The objectives of the present study were (a): to demonstrate the antiproliferative and apoptotic effects of Achillea falcata (A.falcata) extract in human cervical cancer cells (HeLa), and (b): to study the effect of the extract on cellular morphology, cell cycle phase distribution and mitochondrial membrane potential.', 'MTT assay was used to evaluate the anticancer effect of the extract on HeLa cells. Phase contrast, fluorescence microscopy and transmission electron microscopy (TEM) were used to investigate the morphological changes in these cancer cells after extract treatment. Flow cytometry was used to evaluate the effects of the extract on cell cycle and mitochondrial membrane potential.', 'The results revealed that A. falcata extract led to a significant antiproliferative effect in HeLa cancer cells. The extract induced cellular shrinkage, chromatin condensation and appearance of apoptotic bodies which are the hallmarks of cellular apoptosis. TEM results showed that extract-treated cells had nuclear membrane which was hemispherical and the nuclear chromatin was concentrated and bundled on the inner border of karyotheca. The endoplasmic reticulum also became enlarged in the inner segment. The extract also induced G2/M phase cell cycle arrest along with loss of mitochondrial membrane potential.'] Are antiproliferative and apoptotic effects of the ethanolic herbal extract of Achillea falcata in human cervical cancer cells mediated via cell cycle arrest and mitochondrial membrane potential loss?