The decompositions of tertiary stivines (R 3 Sb, R = methyl, vinyl, isopropyl) were studied in an atmospheric pressure flow tube reactor, using D 2 and He as carrier gases. D 2 was used to isotopically label the byproducts in order to elucidate the pyrolysis mechanism. The exhaust products were analyzed by a time-of-flight mass spectrometer. The decomposition of these tertiary stibines in the presence of group III precursors was studied in order to simulate the conditions of organometallic vapor phase epitaxial growth. A comparison between the pyrolysis temperatures, decomposition mechanisms, and surface area effects of these Sb source compounds is presented.