Purpose: To evaluate the effectiveness of punch trabeculectomy in controlling intraocular pressure (IOP) in patients with uncontrolled chronic open-angle glaucoma (COAG) undergoing medical treatment. Methods: This prospective study included 22 patients (27 eyes) with uncontrolled COAC on medical treatment undergoing punch trabeculectomy through a scleral tunnel. The tunnel was created with a 3.5 mm keratome, the tunnel mouth was not sutured but the conjunctival flap was sutured by 8/0 vicryl. The mean surgical time from opening the conjunctiva to closing the conjunctiva was 8 m 59 s. IOP and other parameters were checked on day 1 and subsequently at intervals appropriate to the individual. Results: After a mean period of 22.2 months follow-up the mean IOP was 13.3 mmHg (SD 5.2). There were few transient early post-operative complications; two eyes had a shallow anterior chamber (AC) due to excess drainage, five had IOP above 21 mmHg, which responded to ocular massage, ten eyes had hyphaema less than 1.5 mm and two eyes had no filtration bleb. Conclusions: Punch trabeculectomy is a rapid and effective method of controlling IOP. The complication rate is moderate and mainly transient.