National Physical Laboratory, Hillside Road, New Delhi-110 012 Manuscript received 21 June 1985, revised 20 January 1986, accepted 6 February 1986 Bis-\(P\)-biphenyltin(IV) carboxylates of the type \(P\)-(C3H5 — C6H4)2Sn(OCOR)2, where R=o-CH3 —C6H4, \(P\)-CH3, — C,6H4, CH3-O- C6H4, CH2, — C6H5, and CH= CHC6H5, have been prepared by the reaction of bis-\(P\)-biphenyltin dichloride with sodium salt of respective carboxylic acid in 1 : 2 molar ratio in methanol and acetone mixture. The complexes are characterised by elemental analysis, molecular weight determination, conductivity measurements, infrared and 1H nmr spectroscopy. The carboxylate moiety acts as bidentate in these complexes.