Diphenyltin dichloride forms 1:1 adducts with o-pbenanthroline, 2,9-dimethylp- henanthroline, 2,2’-bipyridy‘l, 4,4’-dimethyl bipyridyl, 2,2’, 2”-tripyridyl pyridine-N- oxide, triphenylphosphine oxide, methyltri-phenylphosphonium chloride, diphenylphosp- hino ethane, -methane oxides and thianthrene-5-oxide. But it forms 2:1 adduct with diphenylphosphino ethane which on oxidation gives tbe corresponding oxide. This may be attributed to steric hindrance. Some physical studies for these adducts are reported. These incinde infrared spectra, conductivity and molecular weight determinations.