In the present work, a series of cyclophosphazenes containing thiazole or thiadiazole rings (5–8) was synthesized. The hexakis-[3′-(1′,2′,3′-thiadiazol-4′-yl)phenoxy] (5) and hexakis-[5′-oxy-2′-methylbenzothiazole] (6) cyclotriphosphazene derivatives were synthesized from the reactions of hexachlorocyclotriphosphazene (1) with 3-(1,2,3-thiadiazol-4-yl)phenol (3) and 5-hydroxy-2-methylbenzothiazole (4), respectively. The octakis-[3′-(1′,2′,3′-thiadiazol-4′-yl)phenoxy]cyclotetraphosphazene (7) was obtained from the reaction of octachlorocyclotetraphosphazene (2) with compound 3. Furthermore, heptakis-(5′-oxy-2′-methylbenzothiazole)monochlorocyclotetraphosphazene (8) was also synthesized from the reaction of compound 2 with 4. All the obtained compounds (5–8) were fully characterized by elemental analysis and spectroscopic techniques (such as mass, 1H, 13C and 31P NMR). The molecular and crystal structure of 6 was also characterized by X-ray crystallography. Compounds 5–8 are reported for the first time in this study. The fluorescence properties of these cyclophosphazene derivatives (5–8) were investigated in tetrahydrofuran (THF) solution.