This is very surprising for us that still most of the peoples are not mentally prepared to accept the fact that some of the human cancers are caused by certain bacteria, viruses, fungi and some of the photosynthetic microorganisms. And, this is found again very shocking if the causal organisms are the worms. A variety of human trematodes developed several fatal diseases like urinary and biliary interruptions, high grade jaundice and even stone formation in human if not treated well within time. Similarly, Schistosoma haematobium causes bladder cancer and Opisthorchis viverrini and Clonorchis sinensis developed cholangiocarcinoma. The present review deals with the study of certain trematodes parasitizing in human developing disease complications causing cancer. And, this is carried out with the help of recent researches done so far in the field of human helminthic oncology and parasitology