It is not unusual to observe in the same eye a chronic glaucoma and a cataract. Surgery may be indicated for one of these diseases separately or for both of them. For simultaneous operation on glaucoma and cataract several attitudes could be discussed: a) cataract surgery and medical treatment of glaucoma, b) glaucoma surgery at first and then cataract surgery, c) cataract and glaucoma surgery at the same time. Since trabeculectomy is used for glaucoma surgery, the author performs the combined method, i.e. the simultaneous lens extraction and the operation of glaucoma through trabeculectomy. The advantages of trabec-lectomy over the other techniques for glaucoma surgery indicated that trabeculectomy over the other techniques for glaucoma surgery indicated that trabeculectomy is the best technique to be used in association with intracapsular cataract extraction. Our material consists of 65 patients, amongst which there are 11 patients with diabetes. 91 eyes have been operated upon during the last 2 years. Most of the postoperative complications, i.e. hyphaema, vitreous haemorrhage and prolapse, pupillary block, postoperatve rise of i.o. pressure are not severe and have no influence in the desired fall of i.o. pressure. It may be pointed out that a permanent regulation of i.o. pressure often occurs only 3 months postoperatively. Finally it can be said that the trabeculectomy associated with intracapsular cataract extraction appeared to be the best operation in case of glaucoma and cataract, provided that on the one hand the vascular status of these patients is controlled and on the other hand the operation microscope is exclusively used in surgery of the trabeculum.