The object of the study is ornaments in the architecture of ancient and modern mosques. Using the example of mosques in Amman (Jordan), traditional ornaments are considered from the point of view of their purpose, content and symbolism, location and plastic organization. The compositional techniques, stylization methods, images used in ornaments are analyzed. In the modern architecture of mosques, continuity in approaches to decoration is combined with the active use of modern technologies in the construction and interpretation of ornaments, their embodiment in the material. Since there are strong changes in the space-planning solutions of mosques in connection with modern functional tasks, it is ornaments that are the most important means of identifying religious buildings. New interpretations of the visual language and the purpose of the decoration of mosques are due to the processes of globalization and the use of computer technologies for the design of structures. The authors conclude that it is necessary to follow the canons of Islamic ornamental motifs when using them in modern architecture, especially in religious buildings. By offering engineering and artistic innovations, architects must preserve the structure, plasticity and symbolism of ornaments in which the philosophy of Islam accumulates.