Research on a variety of languages has shown that vowel duration is influenced by phonological vowel length as well as syllable structure (e.g., Maddieson 1997). Further, the phonological concept of a mora has been shown to relate to phonetic measurements of duration (Port, Dalby, & O’Dell 1987; Hubbard 1993; Cohn 2003). In Levantine Arabic, non-final closed syllables that contain a long vowel have been described as partaking in mora-sharing (Broselow, Chen, & Huffman 1997; Khattab & Al-Tamimi 2014). The current investigation examines the effect of vowel length and syllable structure on vowel duration, as well as how this interacts with durational effects of prosodic focus. Disyllabic words with initial, stressed syllables that were either open or closed and contained either a long or a short vowel were examined when non-focused and in contrastive focus. Contrastive focus was associated with longer words, stressed syllables and phonologically long vowels. Short vowels were shorter when in a syllable closed by a singleton but not by a geminate consonant, while long vowels were not shortened before coda singletons. An analysis is proposed whereby long vowels followed by an intervocalic consonant cluster are parsed as open syllables, with the first consonant forming a semisyllable (Kiparsky 2003), while long vowels followed by geminate consonants partake in mora-sharing (Broselow, Huffman, Chen, & Hsieh 1995). The results also indicate compensatory shortening for short vowels followed by a singleton coda.