Abstract: Background and Objectives: Several studies have been investigated the natural components as an alternative cancer therapy. This study aimed to address the antitumor efficacy of Prunus armeniaca seed extract (PASE) and Prunus domestica seed extract (PDSE). Materials and Methods: Phytochemical analysis and gas chromatography-mass spectroscopy (GC-MS) profile, human breast (MCF-7), hepatic (HepG-2) cancer cell lines and Ehrlich ascetic carcinoma (EAC) were used to determine the anticancer efficacy. Results: Total phenolic, flavonoids, saponin and anthocyanin in PASE were 1291 μg mL–1, 159 μg mL–1, 16 mg g–1 and 65 μg mL–1, respectively. While, in PDSE were 729 μg mL–1, 63 μg mL–1, 7.6 mg g–1 and 89 μg mL–1, respectively. The GC-MS analysis showed that the highest peak area (%) in PASE was octasiloxane-hexadecamethyl (17.04%) and in PDSE was hexadecanoic acid, trimethylsilyl ester (31.92%). In vitro inhibition concentration (IC50) of PASE and PDSE against MCF-7 were 31.5 and 306, respectively. The IC50 of PASE and PDSE against HepG-2 were 22.8 and 430 μg mL–1, respectively. The PASE had a potent anticancer activity higher than PDSE against EAC-bearing mice. Conclusion: PASE had a potent anticancer activity than PDSE due to their phytochemical’s contents.