The kidneys are the paired organs of the urinary tract that have many functions, including excretory, endocrine and metabolic functions. Urinary formation, regulation of acid-base balance and electrolytes, regulation of blood pressure, stimulation of erythropoiesis in the bone marrow, maintenance of bone strength are just some of the essential functions for maintaining homeostasis. Chronic kidney disease is defined as a disorder in the structure and function of the kidney that lasts longer than three months with health consequences. The etiology of chronic kidney disease is different, but it is most often caused by systemic diseases such as hypertension and diabetes. Chronic kidney disease can be classified according to three criteria, namely glomerular filtration rate, albuminuria and cause based. Five stages of chronic kidney disease are currently defined according to a reduction in glomerular filtration. Despite the possibility of early detection of the disease and the implementation of a therapeutic intervention that can reduce and slow the damage, more and more patients are reaching stage 5 or terminal stage of renal disease. Patients in Stage 5 need to be prepared and then treated with one of the renal replacement methods. The methods of replacement therapy are hemodialysis, peritoneal dialysis and transplantation. The types of replacement therapy are home hemodialysis, hemodialysis at the dialysis center, continuous outpatient peritoneal dialysis, automated peritoneal dialysis and kidney transplantation from a deceased donor or living related donor. Elderly patients, with much comorbidity and poor general condition, choose a conservative treatment. Conservative treatment involves patient care without renal replacement therapy. Such care consists of treating symptoms and medical conditions that adversely affect the kidney function and quality of life of the patient. It is necessary to regulate hypertension, diabetes, diet, anemia, phosphates and PTH in the blood and body weight. Conservative therapy patients are also required to provide psychological assistance related to the outcome of their illness, to ensure the best quality of life, to regulate the sleep cycle and thus fatigue. Finally, a palliative care plan needs to be agreed with patients. Chronic kidney disease is one of the leading public health problems and leads to increased morbidity and mortality both in the world and in Croatia. Prevention of chronic systemic diseases and timely care of the patient can prevent further disease progression and impairment of renal function.