Many patients seeking dental care have significant medical conditions that alter both the course of their oral disease and the therapy provided. Treatment of medically compromised orthodontic patients should be directed towards the prevention of oral complication that could be life threatening and hence special precautions are usually required.An orthodontist who is treating medically compromised patients should have a working knowledge of the multitude of medically complex problems. Orthodontists need to be aware of the possible clinical implications of these diseases. He must have a basic working knowledge of patient's disease process and should inform the general physician about the type of procedures planned. Treatment plan should be modified according to effect of the particular disease in the oral cavity.