The present chapter deals with the coarticulatory effects of the contrast of pharyngealisation in Modern Standard Arabic (MSA) and Dialectal Arabic (DA). The first study dealt with acoustic data, based on locus equation (LE) parameters extracted from the production of sixteen subjects from Yemen, Kuwait, Jordan and Morocco who spoke 24 words in MSA and 24 words in DA, with a symmetrical VCV context [iCi, uCu, aCa] where C was either pharyngealised (Ph) /t d s ð / or nonpharyngealised (n.Ph) /t d s ð/. LE parameters were very accurate to reflect pharyngealisation patterns of CV coarticulatory effects according to speech variety and geographical clustering. The second study dealt with EMA data performed on one Tunisian speaker. It provides some observations of the articulatory mechanism of pharyngealisation. This section provides also a comprehensible interpretation of coarticulatory effects of pharyngealisation revealed by locus equation parameters.