In this paper we examine the relationship between specifichead movement events – head nods, often treated as prosodicboundary markers – and syntactic units in Finnish (FinSL) andSwedish Sign Language (SSL). In the study we investigatedthe alignment of head nods with syntactic units on the basis ofa total of 20 (10+10) FinSL and SSL narratives. The results ofthe study show that in both languages head nods appeared similarlyon syntactic boundaries and that the tendency was toalign nods sentence-finally. However, not all head nods behavedthis way: for example, a relatively large number of headnods were also found to occur sentence-initially or elsewherein the sentence. Furthermore, head nods occurring on syntacticboundaries also had non-boundary marking functions, and notall syntactic boundaries occurred with head nods.