Chronic kidney disease is one of the most prevalent diseases in our country, with a significant proportion of patients on renal replacement therapy with hemodialysis. Within this group, arteriovenous fistulas, both native and prosthetic, represent the main vascular access. Ultrasonography has gained an essential role in the construction and monitoring of these fistulas and is used in the presurgical assessment and surgical plan. It also helps identify predictors of early dysfunction and maturation failures, as well as detecting subsequent complications like stenosis and thrombosis. Therefore, ultrasound assessment and bedside ultrasound, or POCUS, are essential resources for physicians who care for patients on renal replacement therapy.