Stille coupling of water-soluble aryl and vinyl halides with alkyl-, aryl-, and vinyltrichlorostannane derivatives (RSnCl3) are effected in aqueous solution using a catalyst generated in situ from PdCl2 and KOH both with and without added PhP (m-C6H4SO3Na) 2. The yields are generally good to excellent, although some limitations of the protocol are described.