Azulejos are one of the most interesting and original decorative element in the portuguese architecture. Azulejos are small square tiles of painted pottery used to decorate both indoor and outdoor of buildings. Azulejos production came in Portugal from Morocco and Spain in the second half of XV century. In a first time they were decorated with geometrical draws following the morish tradition. Since the end of XVI century, with the influence of italian "maiolica" which grows up quickly in the Iberian peninsula, and after of Flemish art, azulejos started to be painted like real pictures, representing religious and daily life scenes, and with the blue monochromy they started to be done polychromy compositions. At the end of XVI we can see a particular evolution of this art: the passage from a production realized by artists to an handmade production. After a baroque and neoclassical period that made an elegant production of works of high level both pictorical and architectonical, in the perfect balance with decorated buildings, since 1850 azulejos production expanded herself to the factory and started to be produced tiles simply covered, that lost the artistic value which they had had till that time. From the beginning of XX century we can find interesting decorations in Liberty style, but this art is distant from architecture and now linked to artistic prodution that uses originality, ignoring any link with architecture, but producing pottery picture. Production technichs have always been the same: to separate colours they use drills or relieves tat produce, in the first case, azulejos in corda seca way, and in the second in aresta way.