This paper aims to study the challenges of Web writing and translation of institutional discourse. More precisely, it focuses on issues of Web writing in a multilingual environment. The analysis relies on the Translation Studies approach regarding Web writing practices. This is done through the study of two examples of institutional discourse in the Arab world: The World Health Organization (Office for the Eastern Mediterranean Region) and General Organization of Information, portal of the Egyptian government responsible for promoting culture and the image of Egypt. This study examines the development of Web translation and writing in its relation with translation professions. The authors analyze specific examples of the characteristics of Web writing in both French and Arabic languages concerning production and content optimization, metadata writing, adaptation to the user and to search engines. Both the core and the form of Web content is focused on the user. The specifics of Web writing will be studied in their relations with the local culture. What are the features of the Arabic user especially Egyptian and/or French-speaking Egyptians? In this context, the authors will consider the linguistic and socio-cultural elements in the process of Web writing of institutional discourse.