A process for the production of alkyltin thiocarboxylic acid esters from alkyltin halides and thiocarboxylic acid esters in the presence of an acid acceptor, which process comprises carrying out the reaction continuously in a reaction system comprising 1 to 5 agitator vessels with an average dwell time of 1 to 60 minutes, at a constant pH value in the range from 3 to 8, and in a temperature range from 40.degree. to 80.degree. C. and separating the product drawn off from the reaction system from the aqueous phase and subsequently drying it.The alkyltin thiocarboxylic acid esters obtained by the process of the invention are used for stabilizing homo- and copolymers of vinyl chloride.