Over the last decades, Ottoman port cities of the Eastern Mediterranean have attracted considerable attention as the nodes of incorporation between the western capitalist system and the Ottoman Empire during the 19th century. İzmir was one of the most prominent port cities of this period in terms of its commercial and demographic structure. A number of influential historians regard the early modern period of Izmir’s history as the beginning of the long incorporation process, which they examine within continuity from the early seventeenth until the twentieth century. This paper argues against this interpretation. On the basis of the evidence offered by tax registers, travelers’ accounts, and city development plans drawn by Ottoman authorities, it will demonstrate that there is a clear-cut contrast between the early modern period and the nineteenth century in terms of the commercial and demographic patterns attested in Izmir. Whereas in the sixteenth century Izmir was a small coastal town, during the first decades of the seventeenth century it experienced a rapid economic and commercial development. Consequently, the port city welcomed new immigrants from various parts of the Ottoman Empire and the Mediterranean basin. Over just a few decades its population increased more than ten folds. These Muslim and non-Muslim newcomers established new ethnically and religiously mixed quarters in Izmir. During the late eighteenth and nineteenth centuries, the city experienced a significant economic boom and simultaneous new migration waves. In this latter period, however, immigrants settled into more homogeneous new quarters. These new quarters also attracted some of the old inhabitants, who helped to consolidate this more homogenous communal structure. Therefore, by the twentieth century the demographic structure of the city was thoroughly transformed. The transformations outlined above argue convincingly against dating the beginning of the incorporation process for Izmir to a period prior to the nineteenth century.