Studies have shown that low quality of life is a risk factor for increased hospitalization, diminished adherence to treatment, and increased morbidity and mortality. Recently, quality of life has been an area of interest in endocrinology. Studies have demonstrated that it is reduced in disturbances such as diabetes mellitus, obesity, thyroid diseases, Cushing's disease, and pituitary tumors. This book aims at reviewing recently published data on quality of life in endocrine diseases. It presents the available data on quality of life in non-functioning pituitary tumors, prolactinomas, acromegaly, GH deficiency, Cushing's syndrome, hypo- and hyperthyroidism, hypogonadism, diabetes mellitus, and obesity.