Purpose: To evaluate the in vitro antiproliferative activity of the extracts of the three plants against a panel of human tumor cell lines representing the most common types of cancer in Jordan, viz, breast and colorectal and skin cancers. Methods: The methanol extracts of the aerial parts of the three plants (Arbutus andrachne L., Chrysanthemum coronarium L., and Teucrium polium L.) were prepared and assessed for antiproliferative activity against six human tumor cell lines (A375.S2, WM1361A, CACO-2, HRT18, MCF-7, T47D) using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide MTT cell proliferation assay. Results: C. coronarium extract, at the concentration range of 25 to 400 μg/mL, significantly inhibited (10 – 50%) the proliferation of the 6 cell lines in a dose-dependent manner, whilst the extracts of the other two plants exhibited weak antiproliferative activity (2 – 10% inhibition). The half-maximal inhibitory concentration (IC50) values of C. coronarium extract against the six cell lines were in the range of 75.8 to 138.5 μg/mL. Conclusion: The methanol extract of the aerial parts C. coronarium possesses a relatively potent antiproliferative activity and therefore might be a potential source of natural compounds that can be developed into new antineoplastic agents. © Pharmacotherapy Group, Faculty of Pharmacy, University of Benin, Benin City, 300001 Nigeria. All rights reserved.