This document describes a list of Modern Standard Arabic closed-class words, which can be used as a stop list for a variety of natural language processing applications. The list contains 740 inflected words and clitics in the Arabic Treebank (ATB) tokenization scheme (Maamouri et al., 2004; Habash, 2010). The inflected words are based on 309 lemmas from the Standard Arabic Morphological Analyzer, SAMA (Graff et al., 2009). To get a copy of the full list, please contact the authors.