Renal replacement therapies (RRT) encompass life-sustaining treatment methods used when the kidneys are unable to perform their basic functions in cases of end-stage chronic kidney disease or acute kidney injury. These therapies primarily include hemodialysis, peritoneal dialysis, and kidney transplantation. Hemodialysis relies on the purification of blood through a semipermeable membrane, while peritoneal dialysis is based on the use of the peritoneal membrane as a natural filtration surface. Both dialysis methods are effective in maintaining fluid, electrolyte, and acid-base balance; however, they differ in terms of application, complication profile, and impact on lifestyle. Kidney transplantation is considered the most effective and permanent renal replacement option when a suitable donor is available. The choice of renal replacement therapy should be determined through a multidisciplinary approach based on the patient's clinical condition, comorbidities, life expectancy, and individual preferences.