This comparative study on the Sign Language of the Netherlands (NGT) and Italian Sign Language (LIS) addresses and discusses a wide range of aspects regarding grammar – the position of the adjectives, numerals and demonstratives, the linear ordering of selected aspectual markers and modals, topicalization, negation, imperative and interrogative clauses, as well as conditional clauses and LIS relative clauses. The study shows that LIS and NGT display a considerable degree of cross-and intra-linguistic variation and tries to assess whether the observed differences can be derived from one universal specifierhead-complement deep structure, shared by all sign and spoken languages. Although further aspects of LIS and NGT must still be examined, the study shows that an antisymmetric analysis of these sign languages is certainly worth undertaking.