From the rather difficult excavations that have taken place in Thebes since the beginning of the last century, many fragmentary but often well-preserved paintings on plaster have been unearthed. These belong to several contexts and periods: House of Kadmos (Late Helladic IIIA), Treasury Room (Late Helladic IIIB1) and Oikopedon Spourli (Late Helladic III). Their iconography, style and technology fit well with other paintings from the Late Bronze Age sites found in the vicinity of Thebes (e.g. Gla and Orchomenos). This paper presents a technological study of the Bronze Age painted plaster from Thebes, Greece. The paintings were investigated by means of X-ray diffraction; stereo, reflected light and scanning electron microscopy; some by laser-induced breakdown spectrometry and by micro-Raman spectroscopy, in order to identify the pigments and the composition of the plaster layers, and to determine the painting technique(s) that the artisans may have employed. The plaster layer onto which the paint layer was applied was often the only layer and consisted mainly of calcite, while a clay plaster formed the backing between the lime plaster coat and the actual wall surface. The pigments identified were: yellow ochre, haematite (red), cuprorivaite (Egyptian blue), indigo and possibly riebeckite for blue, charcoal (black), calcite (white), and a combination of black and red for purple. A detailed macroscopic study of the painted surface revealed several features, which indicated that the technique of al fresco painting was employed extensively, a technique already in use since the start of the Late Minoan I phase on Crete. A generally lower level of quality in the appearance of the later paintings (Treasury Room and Oikopedon Spourli) was also noted, but this was not reflected in the materials used or in their overall manipulation.