Early Iron Age gold buttons from Castro dos Ratinhos, Fortios and Outeiro da Cabeça were analysed by conventional EDXRF, Micro-PIXE, SEM-EDS and Optical Microscopy. EDXRF results point out to a rather homogeneous alloy composition throughout all the analysed buttons. PIXE microanalyses show that all the button components (disk, tab and peripheral grooved decorated rod) have the same alloy composition. PIXE and SEM-EDS microanalyses, supplemented with optical microscopy characterization, show the absence of chemical composition differences between distinct components and joining zones, suggesting that no solder had been applied, i.e. that a partial melting/solid state diffusion process had been used for the welding of button components. Finally, the noticeable similar compositions together with the use of the same welding process and the very similar artefact typologies suggest that those small gold treasures could be interpreted as the result of the work of a single metallurgical workshop, probably located somewhere in the South-Western Iberian Peninsula.