Despite continuous progress in the development of advanced dressing materials, there is a constant need for dressings used in an environment of infected and hard-to-heal wounds. Dressings that meet the above described requirements are products based on chitin and its derivatives. Chitosan and chitin derivative dressings are now becoming a very effective medical device in healing hard-to-heal wounds, as well as in the control of severely bleeding wounds. Chitosan and chitin are particularly valuable raw materials that accelerate wound healing processes, and they are also biocompatible and antibacterial. Dressings made of butyric-acetic chitin copolyester are intended for treating wounds of various aetiologies, including chronic wounds in which the healing process is disturbed by concomitant diseases. Materials based on chitosan are also widely used in the area of heavily bleeding and chronic wounds.