Osteogenesis imperfecta (OI) is a hereditary connective tissue disorder, usually caused by dominant mutations of genes coding for collagen type I alpha chains, COL1A1/A2. Although skeletal manifestations of OI are most readily observable, cardiopulmonary disorders in patients with OI are increasingly recognized as life-threatening but treatable disorders. Unfortunately, the majority of patients with moderate to severe types of OI die from or with cardiopulmonary complications. The lungs and the heart are often unrecognizable and neglected organs in patients with OI. In monitoring of patients with OI, attention is mostly focused on monitoring long bone and spine deformities, and indirectly deformities of the chest wall, which have consequences on the development of lung and the airway diseases. Lung disorder is frequently ignored until breathing problems become severe. An important component in patients with OI is obstructive lung disease, sleep disordered breathing, as well as acute and chronic infection often connected with resultant bronchiectasis. In addition to respiratory complications, some patients with OI have serious cardiovascular problems, including severe mitral valve prolapse, aortic valve insuffi ciency and dilation of the aorta, which require cardiac surgery. The diagnosis and management of the lung and cardiovascular complications in some patients with OI are quite diffi cult. In all patients with OI, it is important to recognize and monitor respiratory and cardiovascular manifestations in order to prevent further progression of any complications.