There are a lot of studies about the Lausanne Treaty which is the last of the treaties ending The First Wald War. However, the studies related to its reflection on public opinion after being signed and how it affected public opinion is limited. In this study it is tried to establish what kind of impact Lausanne Treaty had on Istanbul people by searching the related issues of Tevhîd-i Efkâr an important newspaper of the period. It is going to be tried to put forward how Lausanne Treaty reflected to the public opinion by the way of researching all the related writings published in Tevhîd-i Efkâr in the processes of Lausanne Treaty's being signed, its recognition in Grand National Assembly of Turkey and its implementation.