Portugal continues to present indices of accidents in the construction industry over the desired. This study aims to analyze the principal factors and causes that can origin risk conditions. Based in that analysis it’s possible to begin working in preventing measures in order to decrease those indices. The focus on rehabilitation has increased in Portugal and it is in this kind of construction that difficults appear, mainly motivated by the lack of planning, of local knowledge to work and skilled manpower. The architectural heritage is a short group of works that has relevant characteristics that emphasize problems usually existent in traditional rehabilitation sites. Thus, on the basis of accompaniment of several heritage rehabilitation sites, this work puts forward the main difficults of safety management regarding this type of activity.