Abstract... The study was conducted at the Language Centre of Misurata University, to investigate the ‘markedness’ effect of articulating CCC clusters in onset, and CC, CCC clusters in coda, among Libyan speakers of English. Eckman’s ‘Markedness Differential Hypothesis’ was employed as a theoretical framework to investigate the problem. The instruments used were a list of words containing the target consonant clusters, and unstructured interviews of the participants. 20 students, all studying at the intermediate level at Misurata University Language Centre, participated in the study. The speech samples were analyzed to identify the difficulty of pronouncing the target clusters, and their deviation in Libyans’ English speech. The CCC clusters in the onset and both CC and CCC in coda were the most difficult sounds to articulate. The answer to the research questions was clear that the Libyan speakers of English do have difficulty in articulating the complex consonant clusters because of their absence in their L1. The results of the study clearly prove and support markedness hypothesis. Some recommendations have been made to improve the pronunciation in the areas identified in the present study.