While the English language boasts a century of research into its most frequently-used words, no such attempt has ever formally been made in the Arab world. This pioneering study presents a list of 500 commonly-used words in the Arabic language based on compilations of words gathered from a number of popular reading series in Lebanon, spanning grades K to 3. This list can serve as a powerful tool for language teachers--who face several challenges posed by the inherent nature of Arabic in terms of diglossia, orthography and morphology--and provide them with a handy list of words for their pupils. The study has its limitations in terms of scope, breadth and the nature of the technology used for counting words. Nonetheless, it makes a number of recommendations for the future, including the development of a readability formula based on this list, the expansion of the scope of this word list and improvement to increase its technical accuracy. (Contains 4 tables.)