In today's 21 st century, Carbon nanotubes (CNTs) are the most researched material by world investigation of the growing industry due to their various reasons properties for use in many applications either in medical or other potential applications. Carbon nanotubes become increasingly popular in various fields simply because of their small size and amazing optical, electric, and magnetic properties when used alone or with additions of metals. Carbon nanotubes are described as a cylindrical rolled graphene sheet. They are cap with end containing the pentagonal ring and also cylindrical of graphene with a diameter of 12 nm. Carbon nanotubes have potential therapeutic applications in various fields like drug delivery for API, diagnostics, and biosensing. Functionalized carbon nanotubes can also act as vaccine delivery systems. The basic principle involved in this to link the antigen to carbon nanotubes while retaining its conformation, thereby inducing antibody response with the right specificity. With the increasing interest shown by the nanotechnology research community during this field, it's expected that a lot of applications of carbon nanotubes are going to be explored in the future for medical as well as other file.