Even though there has been a major progress in modern medicine in the past couple of decades, cystic fibrosis still continues being a hard and complex disease for patients and for the medical team treating these patients. The disease can not be cured, but with the optimal treatment a longer life is expected and patients overall health and quality of life is significantly improved. A high-energy diet and pancreatic enzyme-replacement therapy are the main therapeutic modalities in treating patients with cystic fibrosis. It helps patients to achieve normal growth and development in childhood and an optimal and constant body mass later in life. It is also associated with a better pulmonary function with less acute and chronic lung complications. With longer life there is higher incidence of cardiovascular diseases among patients with cystic fibrosis, which is probably a consequence of their diet high in fat.