Abstract The Fe77.5−x−y−zCrxMoyGazP12C5B5.5 bulk glassy alloy was prepared in the shape of rods and ribbons using copper mold casting and melt spinning, respectively. The structure was investigated by X-ray diffraction (XRD) and the thermal stability was checked by differential scanning calorimetry (DSC). It was found that the samples consist of an a single amorphous phase and exhibit a rather wide supercooled liquid region before crystallization. Some characteristic thermal properties of the amorphous samples as a function of the geometrical dimensions are discussed, as well as the dependence of the glass-forming ability on composition. Additionally, some magnetic data like coercivity Hc, saturation polarization Js and Curie temperature Tc are presented.