Since the introduction of the Z-stent by Cesare Gianturco in 1985, the prominent role of endoscopically placed transpapillary endoprostheses as the treatment of choice to relieve malignant biliary obstruction has stimulated much interest and research in the evolution of his initial design. This article reviews the efficacy and limitation of prior Z-stent models in their attempt to relieve malignant and benign biliary obstructions and previews improvements in the design currently being evaluated in a large, multicenter trial.