A method for making sulfur-containing organosilanes of Formula (I): wherein each R.sup.1 is independently selected from the group consisting of a C.sub.1 -C.sub.4 alkyl, a C.sub.1 -C.sub.4 alkoxy, a C.sub.5 -C.sub.8 cycloalkyl, a C.sub.5 -C.sub.8 cycloalkoxy, a phenyl group, or a phenoxy group, a benzyl group or a benzyloxy group; R.sup.2 is a C.sub.1 -C.sub.4 alkyl; and n is a number from 3-4. The method comprises (a) dissolving an alkali metal in a C.sub.1 -C.sub.4 alcohol to provide an alkali metal alcoholate, (b) reacting hydrogen sulfide with the alkali metal alcoholate of step (a) to provide an alkali metal hydrosulfide, (c) reacting an alkali metal with the alkali metal hydrosulfide of step (b) to provide an alkali metal sulfide, (d) reacting sulfur with the alkali metal sulfide of step (c) to provide an alkali metal polysulfide, and (e) reacting a compound of Formula (II): X-R.sup.2 -Si(R.sup.1).sub.3, wherein R.sup.1 and R.sup.2 are as defined above, and X is a halogen selected from the group consisting of chlorine or bromine, with the alkali polysulfide of step (d) to provide the sulfur-containing organosilane compound of Formula I.