We report two cases of massive invasive pituitary adenoma with the unusual presentation of nasal obstruction. In both cases the diagnosis was only made when the obstructing tissue was removed. Cases reported previously have usually presented with severe focal neurological signs or a long history of neurological symptoms. These two cases are unusual in having minimal neurological deficits despite the extension of tumour into the nasopharynx and the middle and posterior cranial fossae. These extensions were well illustrated by computerised tomography. This unusual presentation is discussed with reference to the literature.