Romanization is a particular form of script conversion and refers to the process by which a Roman-based alphabet is created for a language previously written with either a nonalphabetic script or a non-Roman alphabet. Nearly half the world's population today uses the Roman alphabet, and since the late nineteenth century, it has become a charismatic script, to use Max Weber's term, expanding out of its traditional base in Western Christendom. In addition to the success stories in Romania, Vietnam, and Turkey, there have been numerous attempts to Romanize local scripts in Japan, India, China, and Greece, to cite a few examples, which ended up as failures. This article aims at providing a theoretical framework for explaining success and failure of Romanization through a comparative, in-depth study of two speech communities, Hebrew and Turkish. Independent variables such as harmony between language and script, level of literacy, costs of change, past experiences of script conversion, regime type, availability of canonical texts, and attitudes toward the West are discussed as factors that influence the choice of script.