Systemic mastocytosis (SM) is a rare malignant neoplasia, which can create bone complications. The most frequent of those is secondary osteoporosis, sometimes responsible for fractures, especially of the rachis. We report the case of a 53 year-old woman with 3 non-traumatic lombar fractures, leading to the diagnosis of SM, after bone marrow trephine biopsy. We describe the different types of bone involvement in MS, their physiopathology, their diagnosis and treatment, with help of a bibliographic review.