Abstract Reactions of (triethylstannylthioalkyl) trimethoxysilanes Et 3 SnS (CH 2) n Si (OMe) 3 (n= 1, 2) and (triethylstannylthioalkyl) trialkoxysilatranes Et 3 Sn (CH 2) n Sa [hereinafter Sa= Si (OCH 2 CH 2) 3 N is silatranyl group] with methyl iodide are studied for the first time. The results of the investigation of the reaction of 1-(2-alkylthioethyl) silatranes RSCH 2 CH 2 Sa (R= Me, Et) with methyl iodide are also discussed.