Nematodes, commonly known as roundworms, are among the most prevalent and diverse multicellular organisms on Earth, belonging to the large phylum Nematoda. In addition to free-living species, many nematodes are parasitic, infecting plants, animals, and humans. Nematodes possess a wide array of genes responsible for carbohydrate metabolism and glycosylation. The glycosylation processes in parasitic nematodes often result in unique glycan modifications that are not present in their hosts. These distinct glycans can be highly immunogenic to mammalian hosts and play significant immunoregulatory roles during infection. This mini-review article summarises the glycosylation capabilities and characteristics of parasitic nematodes based on glycomic data. It also highlights recent research advances that explore the biological significance of nematode glycans and their potential for diagnostic and vaccine applications.