The main purpose of this paper is to show that Syllable Contact is responsible for the application of an extensive set of processes drawn from Romance languages and to explore the nature and effects of this constraint within Optimality Theory (OT) on the basis of the analysis of these phenomena. All the processes under examination entail a change in manner of articulation and are the following: a) regressive manner assimilation in some varieties of Catalan and in Languedocian Occitan, b) alveolar fricative rhotacism in Majorcan Catalan, dialects of Sardinian and dialects of Galician and c) alveolar fricative gliding in Languedocian Occitan. The analysis of these processes leads to two important theoretical implications. First, it provides strong empirical evidence that SYLLABLE CONTACT cannot be regarded as a single constraint which categorically bans coda-onset clusters with rising sonority, but rather should be broken down into a universal hierarchy of constraints targeting all possible sonority distances between adjacent heterosyllabic segments, as originally suggested by Murray and Vennemann (Language 59: 514–528, 1983) and implemented within OT in Bat-El (Phonology 13: 283–328, 1996), Gouskova (Falling sonority onsets, loanwords, and Syllable Contact, CLS, 2001, Exceptions to sonority distance generalizations, CLS, 2002, Phonology 21: 201–250, 2004), Baertsch (An optimality theoretic approach to syllable structure: The split margin hierarchy, Indiana University dissertation, 2002) and Baertsch and Davis (Zas Papers in Linguistics 32: 1–14, 2003, Syllable contact: relational hierarchy or locally conjoined margin constraints?, 2005, On the relationship between codas and onset clusters, 2007) (see Pons, Els contactes consonàntics en balear. Descripció i anàlisi, Universitat de Barcelona dissertation, 2004a, It is all downhill from here: the role of Syllable Contact in Romance languages, Manchester University, 2005a). Second, it sheds new light on the ordering within the sonority scale of certain classes of sounds, namely liquids and obstruents, whose positions have traditionally been controversial.