A series of novel 2-oxoimidazolidine derivatives were synthesized and their antiviral activities against BK human polyomavirus type 1 (BKPyV) were evaluated in vitro. Bioassays showed that the synthesized compounds 1-((5-(dichloromethylene)-2-oxoimidazolidin-4-ylidene)amino)sulfonylpiperidine-4-carboxylic acid and 4-(dichloromethylene)-5-(cyclobutylsulfamoylimino)-2-oxoimidazo¬lidine exhibited moderate activities against BKPyV (EC50 = 5.4 and 5.5 μM, respectively) that are comparable to the standard drug cidofovir. The first compound exhibited the same cytotoxicity in HFF cells and selectivity index (SI50) as cidofovir. The selectivity index of the second compound is 3 times less than one of cidofovir due to the higher toxicity of this compound. Hence, these compounds may be taken as lead compound for further development of novel ant-BKPyV agents.