2,2-Dichloro-4,4,6,6-bis[spiro(2',2 ''-dioxy-1',1 ''-biphenylyl]cyclotriphosphazene (2) was synthesized from hexachlorocyclotriphosphazene (HCCP) and 2,2'-dihydroxybiphenyl. The mixed substituent chalcone/dioxybiphenyl cyclophosphazenes (2a-h) were obtained from the reactions of (2) with hydroxy chalcone compounds in K2CO3/acetone system. The chalcone-cyclophosphazene compounds were characterized by elemental analysis, FT-IR, H-1, C-13, P-31 NMR techniques. In vitro anti-carcinogenic activities of all compounds were determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MU) assay. Anti-carcinogenic activity of the compounds (2a-h) against androgen-dependent (LNCaP) and independent (PC-3) human prostate cancer cell lines were investigated. Our results indicate that the chalcone-phosphazene compounds (2a-h) have anti-carcinogenic activity on PC-3 and LNCaP cell lines (p < 0.05). The effective dose of the compounds was determined as 100 mu M. (C) 2015 Elsevier B.V. All rights reserved.