Opsismodysplasia is a very rare disorder which causes a serious retardation of developing skeleton. Underdeveloped trabecular ossification, no carpal ossification centers and facial dysmophism are cardinal features of the syndrome. Cartilage of metaphysis is hypertrophic and abnormal high level type I collagen antibodies can be found in this region. There are only 16 previously published cases. We here present a seven-year-old female who was referred with serious retardation of ossification and with no epiphysis development. Hypophosphatemia secondary to tubulopathy was determined as a second major finding. Our case will be the first reported case of this rare disorder associated with hypophosphatemia. Anahtar Kelimeler : opsismodisplazi, tubülopati, opsismodysplasia, tubulopathy