A series of 4-aryl-1,2,3,4,5,6,7,8-octahydroquinazoline-2,5-diones were synthesized by condensing urea with 1,3-cyclohexanedione and appropriate aromatic aldehydes according to the Biginelli reaction. The structures of the compounds were confirmed by elementary and spectroscopic analysis. The compounds synthesized were tested in vitro for their calcium antagonistic activities. BaCl2-induced contractions of rat ileum were inhibited dose-dependently. Compounds 3-8 exerted weak calcium antagonistic activity on smooth muscles compared with the standard nicardipine.