Centromere formation is a complex process that involves the packaging of DNA into a centromere-unique chromatin, chemical modification and the seeding of kinetochore and associated proteins. The early steps in this process, in which a chromosomal region is marked for centromerization (that is, to become resolutely committed to centromere formation), are unusual in that they can apparently occur in a DNA-sequence-independent manner. Current evidence indicates the involvement of epigenetic influences in these early steps. A number of epigenetic mechanisms that can affect centromere chromatin organization have been proposed. Here, the characteristics of these mechanisms and their relative roles as possible primary triggers for centromerization are discussed in the light of recent data.