The term stress (marching) fracture relates to a fracture provoked without acute trauma, on healthy bone and as a consequence of repeated, long-term, rhythmic load [4, 5]. Stress fractures are mostly observed in young people (12-25 years of age) [15]. The course of this phenomenon we found by medical examination; this means that it is found either by detection or spontaneous ambulance reports. The aim of this study is to point at a possible appearance of these fractures at young soldiers and sportsmen. METHODS During the routine ambulance practice, and by the prospective study on 29 subjects, the study was performed by using oral inquiry [9]. The studied individuals were soldiers who were complaining of pain, swellings and redness of the feet. Except clinical orthopedic examination, additional laboratory analysis was made. RESULTS The results are shown in tables. Table 1 shows that stress fractures of metatarsus bones usually appear during the period of first thirty days of the military service, i.e. during the days of the hardest exertion. The most frequent training absence, which is caused by stress fractures, is during this period of time (Table 2). Of all military duties, marching had the biggest influence on appearance of this disease (Table 3). CONCLUSIONS On the basis of available literature it is evident that there are factors which might have the influence on the occurrence of the disease (hypovitaminosis, foot-wear, foot deformation, body weight, muscle fatigue, etc.). Stress fractures are mentioned in connection with some diseases or special clinical deformations such as rheumatoid arthritis, chronic bronchitis, arthrosis deformities, after arthroplastics, Mb. Bechterew, etc. Consequently, stress fractures do not appear only in a healthy bone, as it is defined [4, 5]. In the clinical practice it was established that the diagnosis of this pathology had, in a few cases, the same clinical picture. On the basis of our experience, by observing, we have concluded that stress fractures occur on healthy or changed bones as the result of physical fatigue of the material, and repeated movements. It is still unclear why these changes are unilateral. CONCLUSIONS a) Stress fractures are frequently appearing at young soldiers. b) Most frequently they appear in beginning of hard and exhaustible training.