In this paper the authors describe two different cases of CP negation in Sicilian dialects. The first element is a left periphery adverb that is derived from a grammaticalized negative cleft. The second one is a negative head that is lexicalized when a higher functional projection is activated. While the two items display a set of relevant differences, it is argued that they exemplify two possible cases of syntactic parasitism. The term is used to indicate that either the position of the parasitic element is “borrowed” from another type of category (in the present case it is Focus) or the presence of a given head (a negative morpheme in this case) is licensed by the presence of a different item in a proximate structural position. The existence of similar phenomena is potentially very interesting for the theoretical definition of the syntactic architecture and its economy and design principles