Professional conservation in Mexico in the 1960s with the help of UNESCO and a great number of European conservators. Traditional conservation methods and materials previously had been applied to wall paintings, but the painting and construction techniques and environmental conditions found in Mexico were extremely different to European ones. Over time, Mexican conservators gained experience, and most European techniques were modified to fit Mexican materials and climate. More recently, ethical issues have been under review, e.g. compatibility, which raises serious questions about reversibility. Currently, in situ conservation is favored, always taking into consideration interdisciplinary actions between archaeologist and architects and, more recently, management issues. -- SCMRE