The aim of this paper is to provide an Optimality Theoretic analysis of CV metathesis in one variety of Libyan Arabic. Output forms in which adjacent segments swap places violate the faithfulness constraint LINEARITY. It will, however, be shown that the dialect under scrutiny resorts to metathesis in order to avoid a marked syllable type. The paper will also prove that metathesis is inapplicable to forms in which the stem includes either a long vowel or a geminate consonant.