Findings of preoperative magnetic resonance (MR) imaging and radiologist-directed intraoperative sonography (IOS) were correlated with surgical and pathologic findings in 11 pediatric patients with intramedullary spinal cord lesions. There were seven gliomas and one each of primitive neuroectodermal tumor, venous vascular malformation, neuroenteric cyst, and active schistosomiasis. MR imaging provided discrete preoperative anatomic localization and excluded multicentric lesions but did not reliably distinguish between solid and cystic lesions. IOS helped (a) define the limits of intramedullary mass before the dura mater was opened and (b) differentiate cystic from solid components. The internal architecture of intramedullary lesions, as shown with MR imaging and sonography, was strikingly similar, allowing discrete correlative localization for biopsy or tissue resection. Gadolinium-enhanced MR imaging and IOS are complementary imaging techniques that should be used in concert for the evaluation and management of intramedullary lesions of the pediatric spinal cord. Both techniques display regions of cord abnormality, but neither definitively characterizes underlying tissue histology.