The nematode Caenorhabditis elegans is a popular model organism for studies of developmental biology, neurology, ageing and other fields of basic research. Because many developmental processes are regulated by glycosaminoglyans (GAGs) on cell surfaces and in the extracellular matrix, methods to isolate and analyze C. elegans GAGs are needed. Such methods have previously been optimized for other species such as mice and zebrafish. After modifying existing purification protocols, we could recently show that the nematodes also produce chondroitin sulfate, in addition to heparan sulfate, thus challenging the view that only non-sulfated chondroitin was synthesized by C. elegans. We here present our protocol adapted for C. elegans. Since the purification strategy involves separation of non-sulfated and sulfated GAGs, it may also be useful for other applications where this approach could be advantageous.