AimSasa veitchii extract (SE) has been used as a traditional medicine to treat halitosis, stomatitis, gingivitis, and pressure ulcers. SE exerts various antimicrobial, antiviral, and antitumor effects. Although SE has the potential to inhibit breast, colon, and lung cancer cells, it remains unknown whether these effects can also be applied to other types of cancer. In this study, we explored the antitumor effects of SE in murine pancreatic ductal adenocarcinoma (PDAC) cells both in vivo and in vitro.MethodsFor in vitro experiments, we examined cell proliferation after 48 hours. We evaluated the apoptosis‐and cell‐cycle‐related molecules using immunocytochemistry and immunoblot analyses. For the in vivo study, we evaluated the tumor volume and weight during three weeks of SE administration using an allograft model.ResultsSE showed the antitumor effect in a dose‐ and time‐dependent manner. SE treatment induced apoptosis in higher dose (400 μg/mL) and induced the downregulation of cyclin‐dependent kinases Cdk4/Cdk6 and Cyclin D1 in lower dose (200 μg/mL). In a murine allograft model, tumor volume and weight were reduced by SE administration.ConclusionSE exhibits an antitumor effect against murine PDAC cells in vivo and in vitro.