Аннотация:The authors discussed their experience in investigating 20 patients with maxillary malignant tumors using routine x-ray studies and MR-tomography, and 13 patients, investigated in the same way plus CT. MRT permitted defining a topical localization of a tumor and its spreading to adjacent anatomical regions (the pterygopalatine and infratemporal fossae, pharynx and peripharyngeal space, orbit, buccal soft tissues, and the cranial cavity). MRT was used to differentiate between tumor tissue and inflammation even within the sinus. As to the detection of osseous destruction, CT seemed much more superior than MRT. It was only in one patient that x-ray findings brought about better results than MRT because of artefacts resulting from metal crowns on the affected side.