By means of sodium alkanethiolate (or benzenethiolate) a representative series of alkylthio (or phenylthio) cyclotriphosphazatrienes, N3P3Cl6–n (SR) n, have been prepared and characterised. Very much more pronounced than in alcoholysis or aminolysis, the degree of chlorine replacement in alkanethiolysis is markedly dependent on the reaction conditions. With the alkanethiolates (R= Alk) bis-, tetrakis-, and hexakis-alkylthio-derivatives (n= 2, 4, ...