Abstract: The present invention relates to a method for the treatment of sludges such as sewage sludges, night soils, water supply sludges, sludged deposition in bottoms of rivers, lakes, harbors and seas and industrial waste water sludges. According to this method, a fiber in an amount of 0.05 to 20% by weight based on solids in a sludge to be treated and an inorganic coagulant or polymeric coagulant are added to the sludge to coagulate the sludge, and water is removed from the coagulated sludge to obtain a filter cake having a low water content.