The helminths are broadly categorized into three groups: Nematodes (roundworms), Cestodes (tapeworms), and Trematodes (flukes). In the review of the literature, many helminth species were found that are capable of being transmitted between humans and wild primates. Many, but not all, are intestinal parasites. Particularly in the developing world, chronic intestinal worm parasitism may demonstrate few clinical symptoms and rarely cause mortality. This chapter highlights two types of vector-borne worms that have greater potential to cause serious disease: filariasis and schistosomiasis, both of which are considered to be neglected tropical diseases and have the potential to be transmitted from wild primates. Worldwide, lymphatic filariasis is endemic in 73 countries in Asia, Africa, and the Americas and is considered a neglected disease by the WHO. Some species of freshwater snails harbor schistosomes, and when larval schistosoma are released into the water, humans can become infected; snails in turn become infected through water contamination with human feces or urine.