A prospective study of pseudoexfoliative (PSX) glaucoma was carried out in the Northwest of Spain. In 546 examined eyes with open-angle glaucoma, PSX glaucoma was found in 243 (44.5%). The mean age in eyes with PSX glaucoma was 72.4 years as opposed to 68.2 of the glaucomas without PSX. Intraocular pressure (IOP) and visual field defects were higher in the PSX glaucomas than in the non-PSX (P less than 0.0001), and within PSX glaucomas was higher in males than in females (P less than 0.001). We found no relation between the IOP of one eye and the contralateral in the bilateral PSX glaucomas, while there was a certain relation to the rest of bilateral glaucomas. In 83.9% of the unilateral glaucomas there was PSX. In 68.4% of the eyes with alteration of the field defect degree 3-4, PSX-glaucomas were observed. Finally, 59.6% of the eyes with glaucoma and cataract showed PSX.