This thesis intends to gather the decorated mortar rough coats that have been preserved in the province of Salamanca, to classify them geographically and to study their most remarkable features by describing the materials, techniques and designs most commonly used. The thesis goal is to rescue from the curse of oblivion the techniques used to face an important part of the traditional as well as the academic architecture of the province. Both its study and its documentation should be of use to preserve the remaining mortar coats adequately as well as to use them in new buildings, taking into account their efficiency, durability and their functional and artistic interest, since they are part of a tradition and a cultural background which might otherwise vanish.