A panel painting representing The Pietà by an anonymous author known as The master of Female Half-Lenghts was analysed by a non-destructive XRF technique. The Pietà forms an important part of the permanent exposition of the Fine Arts Museum of Seville. An unusual brownish tonality of the painting led to a research on pigments and their possible changes during the centuries. Portable XRF equipment was used directly “in situ” in the exhibition room. The results showed the use of pigments, commonly applied in that century, lead white, lead-tin yellow, yellow and red ochre, cinnabar or vermilion, some copper based green pigment, azurite and smalt, as well as some organic red and black pigment. The chemical alteration of smalt, whose blue colour is not observed by the naked eye anymore, led to a brownish aspect of the painting. Also several retouches by modern pigments were found, which were first examed by UV light. The comparison to other Flemish paintings held in the permanent Museum’s collection was also carried out. ; Junta de Andalucía 2005/HUM-493