Osteogenesis Imperfecta is a rare, genetically determined disease with several possible complications in anaesthesia. Anaesthesiologists therefore pay special attention to the treatment of patients suffering from Osteogenesis Imperfecta since they commonly suffer from a difficult airway and intraoperative positioning difficulties. We report here the case of unilateral spinal anaesthesia in a patient suffering from Osteogenesis Imperfecta type I. A 28-year-old patient diagnosed with Osteogenesis Imperfecta type I was admitted to the hospital due to lower leg fracture requiring surgical treatment. The patient had blue sclerae, triangular-shaped face, macroglossia, scoliosis of thoracic and lumbar parts of the spine, pectus carinatum and thrombocytopenia. Upon the correction of thrombocytopenia, unilateral spinal anaesthesia with hyperbaric levobupivacain was chosen in order to avoid possible complications typical for general anaesthesia. Consequently, unilateral spinal anaesthesia with a customized local anesthetic could be consdered as a safe anesthetic method for such patients.