A megaureter literally means “big” or “wide” ureter, nothing more and nothing less. It may be primary or secondary, indicating an obstructive problem, or just being wider than normal without any clinical implications or consequences. The underlying causes of a primary megaureter can be classified as refluxing, obstructing, refluxing–obstructing, non-refluxing non-obstructing. The responsibility of the pediatric urologist is to clarify the underlying cause by using voiding cystourethrography (VCUG), ultrasonography (US) and renal scintigraphy. Differentiation of obstructing and non-obstructing cases can be safely done by serial tests. Most of the primary megaureters have a natural course of spontaneous resolution. About 15% of cases show deterioration in renal function and/or severity of hydroureteronephrosis and/or develop stones, infection or symptoms that require temporary or definitive interventions. These interventions can be endoscopic balloon dilatation and stent placement, nephrostomy placement, refluxing ureteral reimplantation, cutaneous ureterostomy and definitive reimplantation with tapering and antireflux mechanism. Since most of the cases are diagnosed at neonatal ages, the initial interventions are temporary approaches until the definitive treatment. The type of intervention should be weighed by consent of parents after informing and discussing about the potential advantages and disadvantages of the possible options.