This article deals with the monthly population reports in order to describe the demographic view of Istanbul soon after the proclamation of the Edict of Tanzimat. Monthly population reports, in the simplest terms, were the jurnals that present the birth, death, incoming and outgoing migration (transported population) of the population and the amounts of subjects and foreigners visiting Istanbul as guests. The data presented by the reports on the population of Istanbul, including Bilâd-ı Selâse (Eyüp, Galata and Üsküdar), which consists of Muslim, Greek, Armenian, Catholic, Jewish and Gypsy elements, were analyzed according to various parameters. Various inferences have been made on issues such as the distribution of the population of Istanbul according to religious communities/nations, arithmetic increase/decrease trends, adult/child mortality rates, geographical mobility and migration. Findings on geographical mobility were shared, based on the data on immigration (transfer of population) and arrivals/departures between Istanbul and the provinces in the reports. As a result of the study, it has been concluded that the population of Istanbul exhibits negative natural growth characteristics, so qualified immigration from the provinces was needed in order to keep its population and labour force dynamics. According to the average of all reports, the Muslim population, which constitutes 46,5% of the total Istanbul population, had the lowest birth rate and the lowest male birth rate per adult male. In addition, based on the report, an attempt was made to calculate the total population of Istanbul.