Chairside investigations are simple; require inexpensive equipment and rapidly doing procedures. They do not require specialized training. It is carried out conveniently in a clinic or dental office set up. Dentist should be aware of the investigations, which may be required to establish diagnosis of general medical and surgical problems and of the principles of treatment including drug prescriptions. Doctors and dentists should routinely explain the nature of investigations and obtain verbal informed consent for invasive or risky procedures, signed, dated, witnessed informed consent. Chairside investigations hence serve as an important tool in assisting the oral physician to confirm the diagnosis and check out the various treatment plans according to the patients' needs. This dissertation deals with the chairside investigations in dentistry.