The visual performance of Al- Sayyida Nafisa Mosque Square in Cairo is analyzed in this paper. The aim of the present study is to derive a proposed evaluation model that service as a tool for evaluating the visual performance of religious urban open spaces. The research also tries to reach the best visual basics and criteria which support the design and planning process that must be taken in consideration when dealing with the religious urban open spaces. Research results showed that legibility, identity, determinants, aesthetics consistency, sense of nature, and supplements of urban open space help in enhancing the visual performance of urban spaces. We concluded that urban designers can enhance the visual performance by achieving the mentioned components appropriately.