We present the case of a 43-year-old man with neurofibromatosis type 1 who developed elephantiasis neuromatosa of his left leg. The gross limb enlargement was extremely disfiguring, and resulted in such severe disability that he was only able to walk a very short distance using crutches. Previous debulking procedures had resulted in massive blood loss, and prior to attempting further surgical intervention MRI studies were requested. Taking advantage of the excellent tissue characterisation and multiplanar imaging capabilities of MRI, we were able to assess the extent of soft tissue and osseous involvement. The use of recently developed MR angiographic sequences enabled us to non-invasively provide detailed images to assess the relationship of the lesions to the major vessels, as well as the vascular supply and angiographic features of the lesions themselves. This article describes our MRI-based findings, which precluded debulking surgery in this unusual manifestation of neurofibromatosis.