Glaucoma drainage devices have an established position in the surgical treatment of glaucoma, and moreover their use has grown rapidly in recent years. The aim of the study is to discuss the technique and complications of Ahmed glaucoma valve implantation – one of the most frequently used filtering systems in the treatment of difficult cases of glaucoma. Ahmed glaucoma valve implantation is an effective and relatively safe surgical procedure. The effectiveness of the method, according to various literature reports, is estimated at approximately 45–64% in a 5-year follow-up. Traditionally, Ahmed glaucoma valve implantation has been reserved for the treatment of glaucoma refractory to multiple filtration surgical procedures. Currently, this procedure is recommended for patients with risk factors for failure of trabeculectomy with antimetabolites. The current literature shows the potential role of Ahmed glaucoma valve implantation also as a primary surgical option in selected glaucoma cases, for example in patients with a higher risk of infection.