A series of phosphines, P(biphenyl)(n)Ph3-n has been used as co-catalyst in the palladium catalyzed Suzuki cross-coupling reaction of aryl-bromides and -chlorides. The effects of the phosphine, palladium source, base, solvent and promoter salt were investigated. High conversions and turnovers were obtained in all studied phosphines, particularly using P(biphenyl)Ph-2 which can be interpreted by the contribution of steric and electronic effects. (c) 2006 Elsevier B.V. All rights reserved.