Background: To study the anticancer activity of Plantago major, we assessed the effect of ethanolic, methanolic and acetonic extracts of this plant on HCT-116, SW-480, and HEK-293 cell lines as control. Methods: The cytotoxic activity, biocompatibility, and toxicity were evaluated by MTT assay, hemolysis, and Artemia salina-LD₅₀ (on mice) tests, respectively. The analysis of the extracts was performed by GC-MS analysis. Results: The results showed that all the extracts had the most antiproliferative properties on the HCT-116 cell line. The P. major root extract  was more effective than the aerial parts, and IC₅₀ values for ethanolic, methanolic and acetonic root extracts were 405.59, 470.16, and 82.26 µg/mL, respectively on HCT-116 cell line at 72 h. Hemolysis degree of the ethanolic extract of  aerial and root parts were approximately 1% at 400 μg/mL.. Using the ethanolic extracts, the Artemia survived every concentration, and no toxicity was observed. One week after the oral administration of different parts of P. major extracts, none of the mice died, even those were administered 2000 mg/kg. The results of GC/MS analysis showed that P. major extracts contain potential anticancer compounds, such as stearic acid (8.61%) in aerial parts of methanolic extract and 1,2- Benzenedicarboxylic acid, mono(2-ethylhexyl)ester (88.07% and 40.63%) in aerial and root parts of acetonic extract of P. major. Conclusions: Our findings suggest that the P. major is a source of potential compounds with antiproliferative properties.