Pyrazole-derived bidentate ligands (P, N-donor) with bulky substituents at the 3-position of the pyrazole, 1b–d, were used with Pd2 (dba) 3 to carry out efficient Suzuki coupling reactions with both aryl bromides and chlorides. Enhanced catalytic activity on account of steric crowding in the metal complex suggested participation of a chelated structure in the intermediate catalytic steps.