Sacral stress fractures are rare overuse injuries predominantly perceived in female long-distance runners. Our case report describes left-sided sacral wing stress fracture followed by contralateral sacral wing fracture after return to running. A 21-year-old female amateur long-distance runner presented with nonspecific low back and left buttock pain. Plain radiograph at presentation was unremarkable. Magnetic resonance imaging (MRI) revealed extensive bone marrow oedema in the cranial part of the left sacral wing and oblique fracture line. After six weeks of moderate training and two months of tailored running program she felt sharp pain in her right buttock during landing on her right leg. MRI confirmed contralateral sacral wing stress fracture. Additional two-month program to correct lumbar hyperlordotic posture with relaxation techniques and stretching of quadratus lumborum, psoas, multifidus and rectus femoris muscles was carried out. Strengthening of the abovementioned muscles was also done together with abdominal wall muscles and gluteals to stabilize the lumbar spine. She regained full level of training six months after the second fracture. Two years after the second stress fracture of the sacral wing she is free of pain, running about 60 to 70 km per week. Despite rapid rehabilitation program after first sacral stress fracture, contralateral stress fracture occurred. After a few months of additional conditional training and strengthening of lumbar, abdominal and pelvic muscles she regains her long-distance running including four marathons without obstacles. From this case we can assume that following proper rehabilitation program with correction of hyperlordotic posture sacral stress fractures can be avoided.