Ohmic contacts for holes were formed on naphthalene tetracarboxylic anhydride films (NTCDA) at Pd-doped p-type film/metal junction. The injection current density reached 10Acm(-2) at a low bias field of 1.25 x 10(4) Vcm(-1). Pd was revealed to be a candidate for a permanent dopant that can act as an electron acceptor in the formation of p-type organic semiconductors.