The seismic assessment of culturally and historically significant listed buildings is a demanding task that requires the involvement of various parties, from the building-owners and housebuilders to the engineers and monument conservators. High demands on the assessment and its results are generally confronted with very complex and heterogeneous load-bearing structures and non-structural elements. To meet these demands, specialized expertise and experience on the part of the engineers carrying out the assessment and a thorough search for and study of information and documentations in co-operation with all parties involved forms the basis. In addition, appropriate quality assurance and good communication between all parties involved are required. How the building-owners and clients organize the assessment, whether they clearly define requirements and how they shape and manage the process plays an important role in achieving these goals. The contribution summarizes findings and recommendations for the assessment of culturally and historically significant listed buildings in Switzerland based on practical experience. It shows best practice in terms of organization, procedures, methods and calculations.