The solid complexes [Zn(Hhna) 2 (H 2 O) 2 ], (PPh 4 ) 2 [MoO 2 (hna) 2 ], [Pd(Hhna) 2 ], [Pt(PPh 3 ) 2 (hna)], [Pd(bpy)(hna)], [Pd(phen)(hna)], [Ag(Hhna)(H 2 O) 2 ] and [Ag(Hhna)(PPh 3 )(H 2 O)] (H 2 hna=2-hydroxy-1-naphthoic acid) were prepared and characterized by IR, UV–vis, 1 H NMR, 13 C NMR, 31 P NMR and mass spectrometry, and by elemental analysis and thermal measurements. 2-Hydroxy-1-naphthoic acid coordinates the metal ions in either binegative or mononegative bidentate manner through the deprotonated hydroxy and the deprotonated carboxylate oxygen or the carboxylato oxygen atoms. The crystal structure of [Pt(hna)(PPh 3 ) 2 ] has been determined, the Pt(II) center displays a square-planar geometry through the binegative bidentate 2-hydroxy-1-naphthoic acid dianion.