Two types of arsenopyrite are found in the Pezinok deposit: fine-grained gold-bearing arsenopyrite I with average gold content 110 ppm and younger coarse-grained arsenopyrite II without gold or with a low gold content (on the average 0.17 ppm). Arsenopyrite I is the most significant gold-bearing mineral in the Pezinok-Kolarsky Vrch Mt. Sb-Au deposit (ICP/MS analyses by laser-beam ablation revealing gold grades at high as 378 ppm). ¹⁹⁷Au Mössbauer study of two arsenopyrite separates showed that gold is present exclusively in a chemically bound state with isomer shift values of 3.25 mm.s^-1 and 3.62 mm.s^-1, respectively. The gold-bearing arsenopyrites exhibit strong zonation patterns. Generally two extreme types of growth zones with different compositional trends can be distinguished.The first zone has antimony, sulfur and arsenic contents around 0.6–1.0 wt. % and 40–41 wt. % respectively. This zone is followed by the second one, which is also strongly zoned and has arsenic and sulfur contents around 43–45 wt. % and 19–21 wt. %, respectively. Antimony contents are 0.2 wt. % within the second zone,which is considered to be the most probable carrier of chemically bound gold.