Conditions in the town of Lowicz became dangerous from the point of view of hygiene as well as from that of the Security Police, owing to these illegal migrations of Jews. The District President of Lowicz therefore, began to install ghettos in his district in order to avoid these dangers.

The experiences in the district of Lowicz, after ghettos had been installed, showed that this method is the only one suitable for dispelling the dangers which emanate repeatedly from the Jews.
The necessity of erecting a ghetto in the City of Warsaw as well became more and more urgent in the summer of 1940, since more and more troops were being assembled in the district of Warsaw after termination of the French campaign. At that time the Department for Hygiene urged the speedy erection of a ghetto in the interest of preserving the health of the German Forces and of the native population as well. The original plan of establishing the ghetto in the suburb of Praga as intended in February 1940, would have taken at least 4 to 5 months, since almost 600,000 persons had to be moved. But since experience showed that greater outbreaks of epidemics might be expected in the winter months and since for this reason the District Medical Officer urged that the resettling action ought to be completed by 15 November 1940 at the latest, the plan of establishing a suburban ghetto in Praga was dropped; and instead, the area which hitherto had been used as a quarantine area for epidemics was selected for use as a Jewish residential area. In October 1940, the Governor ordered the Commissioner of the District, President for the City of Warsaw, to complete the resettlement necessary for establishing the ghetto within the City of Warsaw by 15 November 1940.

The ghetto thus established in Warsaw was inhabited by about 400,000 Jews. It contained 27,000 apartments with an average of 2 1/2 rooms each.