This paper investigates the process of word-final consonant cluster simplification in Québec French. Three categories of clusters are distinguished:(1) those that may be reduced in all lexical items (unrestricted simplification), (2) those that may be reduced in some lexical items but not in others (lexicallydetermined simplification), (3) those that are always stable. Consonant deletion is motivated by two distinct factors: the Sonority Sequencing Principle and a principle requiring that every segment be perceptually salient. The likelihood that a consonant deletes correlates with the degree to which it violates one of these principles. Appeal to perceptual factors explains in particular two tendencies. First, final stops are less susceptible to deletion than other consonants. Second, cluster simplification correlates with the amount of contrast within the cluster, in terms of voicing, manner and place of articulation. This analysis of cluster reduction supports the integration of perception in phonological theory advocated in a growing body of work. It is formalized within Optimality Theory and uses in particular perceptually-motivated markedness and faithfulness constraints militating against perceptually weak segments.