Arsenopyrite occurs at the Dubrava antimony deposit (Central Slovakia) in quartz veins together with pyrite. Arsenopyrite is also found as impregnation around quartz veins in granodiorites and migmatites. On the basis of analysis of arsenopyrite by electron microprobe the average content of arsenic (in atomic %) in arsenopyrite is 31.67, which indicates temperature of formation about 425°C, resp. 395°C. These data are compared with the analysis obtained by X-ray diffractometer: the average As atomic % is 31.72, indicating temperatures about 400–430°C. Microthermometric measurements made on fluid inclusions in quartz associated with arsenopyrite-pyrite mineralization gave temperatures about 325°C. All the above mentioned temperature measurements revealed that the sulphide mineral formation in Dubrava began at a high temperature.