An increasing number of large cities in the Western European countries are planning to open bathing sites in the rivers that flow through them. In the countries that are EU members, the authorities base the authorisation to open a site on the achievement of the microbiological quality standards set by the 2006 framework directive on bathing water. Urban bathing is therefore generally approached from the angle of bacteriological quality (a supposed guarantee of health safety for the public). This report, based on a sociological survey conducted in Paris and Berlin, highlights other dimensions of the challenge of reopening bathing in urban rivers, taking a narrower view than that of urban strategies but paying attention to the local dimensions of this challenge.