Meaning extraction on the basis of available lexical and grammatical information, i.e., syntactic parsing, is gaining attention as a crucial element in reading comprehension in L1 and L2 settings (Grabe & Stoller, 2013). However, the role that syntactic knowledge plays in the “L2 threshold" required for fluent reading comprehension has yet to be fully defined (Laufer & Kalovski, 2010). Exhibiting a telegram-like syntax, English newspaper headlines represent a reading comprehension challenge for English L2ers because of the presence of non-canonical structures and grammatical violations that include ellipsis of grammatical categories. This study explores the role of syntactic knowledge in interpreting/comprehending newspaper headlines (of different syntactic types and difficulty). Participants of this study (N=48) are Arabic-English L2ers classified into three groups of readers; a proficient reader group (N=14), an intermediate reader group (N=20) and a poor reader group (N=14). The study employs four tasks: A speed reading task (Ten (400 word) reading comprehension passages) (Millett, 2013) (used with permission); a cloze test (Brown, 1980) (used with permission); a 30-minute essay writing task; and a newspaper headline interpretation task. The findings point to: (1) a significant positive relationship between learners' reading comprehension abilities and syntactic knowledge; and (2) a joint role played by syntactic parsing and lexical knowledge in enabling accurate interpretation of headlines. Here, sufficient lexical knowledge was not enough to guarantee adequate comprehension of a headline. The concept of a vocabulary or a syntactic threshold was disconfirmed.