The aim of the presentation is to discuss present pathogenetic opinions related to the biology of long bone healing disorders. Despite the development of basic studies used in this range, long bone healing disorders still pose on essential clinical problem. The Development of tissue engineering and gene therapy has increased the possibilities of treatment of discussed problems. Many years of basic research have resulted in a number of histochemical and of morphogenetic stimulation discoveries, especially in range of cytokines, prostaglandines and bone morphogenetic proteins (BMP). Some of them are currently synthetized and available in practical use, but unfortunately expensive. Research studies refer to groups of essential problems in process of long bone healing disorders treatment. One of the problems is a “substantial” stimulation of bone union. It concerns calcium-phosphorus balance including extremely essential function of hormones and group D vitamins. Another problem is a “mechanical” stimulation of bone union. It refers to the function of bone healing biomechanics including the piezoelektric effect as it is caused by interfragmental compression within the axial skeleton as well as the effects of distraction forces in peripheral skeleton. The biology of long bone healing disorders is a consecutive essential investigative element which facilitates understanding of bone union pathology. As it is well known conditions of long bone union progress depend on location, type and character of fracture, primary complications and biological potential of the patient. Despite this fact bone healing disorders are quite common. The paper shows in a practical manner elements of theoretical bases of long bone union and possibilities of their practical use in current clinical work.