This study focuses on nominal pluralization in Sign Language of the Netherlands (NGT). The aim is to offer a comprehensive description of nominal pluralization processes in the language, based on both corpus data and elicited data, taking into account potential phonological restrictions. The results reveal that NGT nouns can undergo several pluralization processes, the main ones being simple reduplication (i.e., repeating the noun sign at one location) and sideward reduplication (i.e., repeating the noun sign while moving the hand sideward). The choice of pluralization process depends on phonological properties of the base noun: (i) nouns that are body-anchored or involve a complex movement undergo simple reduplication; (ii) nouns articulated at the lateral side of the signing space undergo sideward reduplication; (iii) nouns articulated on the midsagittal plane can undergo both simple and sideward reduplication. Strikingly, the data show considerable variation, and all types of nouns can be zero-marked, that is, plural marking on the noun is not obligatory. The results further suggest that all nouns can undergo at least one type of reduplication. Thus, while phonological properties of the base noun influence the type of reduplication, they do not block reduplication altogether. Plural reduplication in NGT is therefore less constrained than has been reported for other sign languages, where certain noun types cannot undergo reduplication. This shows that reduplication – despite being iconically motivated – is subject to language-specific grammatical constraints.