Although the history of immobilized enzymes and their applications in different fields are traced back to the second half of the twentieth century, their importance in bioreactors and biosensors highlighted at the turn of the current century is under active consideration in these days for broad-spectrum applications in different medical fields. Thus, this article presents a review of the literature concerning the current and future role of the immobilized enzymes in different medical fields. As the author and his supervised research groups have also been actively involved in research on immobilized enzymes, he has also made some input with a recommendation to revise the current classification of immobilized enzymes basically into “Naturally Immobilized” and “Artificially Immobilized Enzymes”, keeping the sub-classification intact. He has also suggested the development of some medical products based on the results of his research groups.