Imaging is fundamental in pre-operative evaluation for cancers of anterior cranial base and ethmoido-sphenoidal region, particularly because clinical examination is poorly contributive and cannot evaluate the tumoral extension. Radiological data are based on CT-scan and MRI. The first goal of radiological evaluation is to recognize the presence of a tumor and to differentiate it from inflammatory lesions, which is not always very easy. The second aim is the evaluation of tumoral extension, particularly towards the intra-cranial cavity and the orbit. It leads to an extension grading which is essential for the choice of a therapeutic strategy (inductive chemotherapy, surgical approach, radiotherapy). The third goal of imaging examination is the evaluation of tumoral response to pre-operative inductive chemotherapy.