We report a case of neuroblastoma diagnosed in an 8-month-old infant who was being followed-up due to antenatal hydronephrosis. Postnatal imaging findings were suggestive of bilateral ureteropelvic junction (UPJ) obstruction. A left pyeloplasty was performed during the postnatal third month. An early postoperative computed tomography (CT) scan, performed because of considerable decrease in hemoglobin/hematocrit (Hb/Htc) values, revealed negative results for any kind of localized collection of fluid or tumor. At the postoperative fourth month, postnatal ultrasonography (USG) revealed a solid left adrenal mass. Blood and urine test results were suggestive of a neuroblastoma. On surgical exploration an adrenal mass was excised. Pathologic examination confirmed the diagnosis of neuroblastoma. The patient had stage 1 disease with favourable histopathologic features. This low-risk tumor, can be treated with primary surgery alone with excellent outcomes. Neuroblastomas either detected by mass screening programs or diagnosed incidentally on urinary tract imaging can be expected to be well localized and have a good prognosis.