Pyrido[2,3-d]pyrimidinones and thiazolo based scaffold were reported to exhibit valuable anticancer activity and inhibit EGFR tyrosine kinase receptors wild and mutant types as well. So new series of 6,8- diaryl pyrido[2,3-d]thiazolo[3,2-a]pyrimidinones 2a-c was synthesized and their chemical structures were confirmed through different spectral analyses including IR, 1HNMR, 13CNMR and mass spectroscopy. Anticancer evaluation was performed through screening for these compounds against A-549, PC-3, HCT-116, and MCF-7 cancerous cell lines at a dose of 100 in comparison with erlotinib. The antiproliferative activity revealed that compound 2a was excellent and approximately equipotent with the reference (IC50= 13.25 and 11.05 μM) which implicated that substitution at position 6 and 8 greatly affect the cytotoxic activity. Furthermore, the promising compound 2a was subjected to molecular docking analysis against EGFRWT and EGFRT790M kinases to examine the binding mode and elucidate the mechanism of the promising cytotoxic activity. Finally compound 2a has been shown to be good candidate that deserve further investigation.