This study aims to examine the history of the Military Office building, which was built in addition to the Sarikisla building in Izmir, one of the most important port cities of the Ottoman Empire, and to emphasize the importance of this building in terms of architectural history. The Military Office building, which was dated to the early 20th century, was destroyed in 1955 after being used for nearly 50 years, and was replaced by the space called Konak Square today. However, neither Sarikisla nor the Military Office building were forgotten after their destruction. Both structures are still present in the collective memory of the citizens, albeit indistinctly. Orientalism, which is the dominant style of the Military Office building, is basically a field of thought founded on the East-West duality. The main motivation for the artistic counterpart of this broad-framed field of thought lies in the mysterious and mystical world attributed to the East by the West. The Eastern-inspired Orientalism movement, which was popular in European architecture in the first half of the 19th century, was also reflected in Ottoman architecture as a part of the architectural interactions of the period. First examples of Orientalist architecture began to be seen in the capital, Istanbul, and in port cities such as Thessaloniki and Izmir, which had close relations with Europe. But it’s a fact that, there is no comprehensive study on orientalist architecture in Izmir. It is difficult to make an inclusive and detailed assessment, as the structures showing these features are few. However, the fact that the Clock Tower, which is one of the most important structures of the city, is in the orientalist style and it is a sign that this style has a considerable effect on the city, especially at the turn of the century. The Sarıkışla building, dated 1829, to which the Military Office building was added, is one of the most important structures of the city with its location and size, despite its plain character. Military Office building, on the other hand, is a qualified structure that bears the characteristics of the orientalist style in its architectural elements and decoration motifs in a way that contrasts with Sarikisla. Despite its special architecture, it is not possible to reach a detailed research or drawings on the structure of the Military Office building. There is also no information on the architect of the building. Only some predictions can be made about this subject. Raymond Charles Péré, the architect of the Clock Tower, which was built in 1901 right in front of the Military Office building and also has orientalist features, is the first name that comes to mind. The fact that the architect of the fountain pool in the courtyard of Sarıkışla is also Péré strengthens this possibility. As a result of the information obtained within the scope of the study, it was determined that the construction date of the building should most probably be between 1913 and 1922.