EN
This paper aims at presenting an OT account of the basic syllable structure of Ukrainian. Among the specifically Ukrainian syllable-driven processes that are considered are onset maximisation, prothesis, voice assimilation, as well as the behaviour of clusters of obstruents agreeing and disagreeing in voicing, sonority plateaus and extrasyllabic sonorants. Optimality Theory is shown to successfully handle dialectal variation in the application of prothesis, as well as the transparency effects in voice assimilation.