Turcot's syndrome is a combination of multiple adenomatous gastrointestinal polyps and neuroepithelial tumors of the central nervous system (CNS). A 16-year-old man presented with Turcot's syndrome consisting of nonfamilial colorectal polyposis and multiple fibrillary astrocytomas accompanied by ruptured intracranial arteriovenous malformation (AVM) manifesting as generalized epileptic activity. Multiple CNS tumors are extremely unusual in Turcot's syndrome. This is the first description of Turcot's syndrome associated with an intracranial AVM. This case may correspond to a new phenotypic variant of colonic polyposis syndrome.