We report on an investigation of inter-consonantal intervals (ICIs) in sequences of two, three and four stops within and across word boundaries in Tripolitanian Libyan Arabic (TLA). This variety of Arabic has been described as allowing vowel epenthesis in all consonant clusters . Our investigation was motivated by the question of whether some of the ‘epenthetic vowels’ of TLA are better characterized as ‘excrescent vowels’, following the distinction made by . To answer this question, we analysed ICI durations at normal and fast speaking rates across permissible stop sequences within and across word boundaries. We also investigated the relationship between ICI duration and voicing. Our results are consistent with the observations presented in , but show that there is indeed evidence for the existence of both epenthetic and excrescent vowels in TLA.