The 1H-phosphirenes 9 a - g were alkylated by the trifluoromethanesulfonate esters 10 a,b to furnish the stable phosphirenium salts 11 a - i. The phosphirenium salts 14 bearing two identical exocyclic substituents at phosphorus were obtained by reactions of the silyl-substituted 1H-phosphirene 12 with a twofold molar amount of the esters 10 a,b. As examples for the reactivity, the salts 11 b,d were subjected to hydrolysis (→ 15 a,b) and 11 c to methanolysis (→ 16).