3 patients presented with non-functioning pituitary adenomas: a 50-year-old woman who had an adenoma that had not increased in size for 3 years; a 68-year-old man with an adenoma that was undiagnosed for 5 years and led to pituitary insufficiency and bitemporal hemianopsia; and a 64-year-old woman, who had refused therapy and follow-up after diagnosis of the adenoma 20 years earlier. She was admitted with a hydrocephalus, pituitary insufficiency, and severe visual loss. The clinical symptoms of pituitary adenomas are caused by the mass effects of the tumour and may vary considerably between patients. Transsphenoidal surgery is indicated in cases of suprasellar extension with compression or impending compressing of the optic chiasm. A 'wait-and-see' approach can be used for patients with smaller tumours and no visual field defects. The natural course of these adenomas is such that lifelong follow-up is necessary. Postoperative radiotherapy can be effective in reducing recurrence rates without negative effects on quality of life.