Ulwa, a Papuan language spoken in the Sepik region of Papua New Guinea, has nominative-accusative morphosyntactic alignment. In addition to a typologically unusual passive construction, Ulwa exhibits two other valency-reducing phenomena, both of which resemble antipassivization. One of these constructions involves a special verbal prefix, but differs from canonical antipassive constructions in that it disallows the overt expression of a demoted object. In the other construction, however, which exhibits no special verbal morphology, the logical direct object is expressed with obligatory oblique marking. Although antipassives are often explained as syntactic operations that are motivated by pragmatic considerations, the situation in Ulwa appears to be different. Rather, antipassive constructions in Ulwa are generally motivated by syntactic constraints. These constraints have nothing to do with the requirements of some ergative languages to enable an actor to serve as a pivot, but rather depend on surface word order. This paper examines the relationship between syntax and pragmatics in valency-reducing strategies. It also suggests how the facts of Ulwa pose challenges for case-absorption analyses of antipassives.