Humans are hosts of nearly 300 species of parasitic worms and over 70 species of protozoa, some derived from our primate ancestors and some acquired from the animals we have domesticated or come in contact with during our relatively short history on earth. Our knowledge of parasitic infections extends into antiquity, and descriptions of parasites and parasitic infections are found in the earliest writings and have been confirmed by the finding of parasites in archaeological material. Humans have also shared a prolonged history of co-existence with parasites residing within their bodies. Both developing and developed countries are affected by parasitic infections. It is established that different parasites could alter humans' immune response. It is now believed that certain parasites either by their own existence or by their products might be used to alleviate diverse inflammatory, autoimmune, and allergic, in addition to other diseases. This review aimed to introduce an appraisal of variable studies and literature pursuing the potential role of different types of parasites and/or their products as therapeutic tools in discrete forms of morbidities.