A new series of benzimidazothiazole derivatives has been synthesized. The structure of the products was confirmed by spectroscopic techniques such as IR, NMR and mass spectroscopy. The tested compounds were evaluated for their anti-inflammatory activity either in vitro through the COX enzyme inhibition assay, or in vivo through carrageenan paw edema technique. Results revealed that compound 25 and 29 represented the most active ones among the entire series with % inhibition 72.19, 72.07 for COX-1, and 87.46, 87.38 for COX-2, respectively. Interestingly, all synthesized compounds exhibited IC values less than both reference drugs celecoxib and naproxen, indicating their superior potency. For compound 25, it showed about 340 and 198 times more potent than celecoxib and naproxen respectively as COX-1 inhibitor (IC value 0.044 vs. 15.000 and 8.700 µM), and 10 and 115 times more potent than the same drugs as COX-2 inhibitor (IC value 4.52 vs. 40.00 and 520.00 nM). The antitumor activity of the products was also evaluated and the results obtained are consistent with those obtained by the anti-inflammatory screening where compounds 25 and 29 proved to be the most active ones among the other compounds with %GI ranging from 31.5 to 62.5% and they exhibited the lowest IC values as well. The ADMET analysis of the tested compounds was also performed in addition to the molecular modeling studies that included flexible alignment, surface and electrostatic maps in addition to the Lipinisk's rule of five.