Diabetes is a condition where the body is unable to regulate the amount of glucose in the blood due to lack of insulin or it is the body's inability to produce insulin.If left unchecked and uncontrolled, diabetes can lead to serious conditions including heart attack, stroke, blindness and kidney failure. Hence the patient has to constantly monitor the blood glucose level to keep it under control. Most current methods for self-blood-glucose-monitoring are invasive which require a blood sample for each test.The blood sampling can be painful and cause calluses to form.Hence Non-invasive methods are being researched upon as an alternative to invasive methods. This book describes a Non-Invasive Blood Glucose monitoring System by using Near Infrared Spectroscopy Technique. This works by projecting Near Infrared radiation on the finger of a subject and sensing the resultant radiation after absorbance. Immediately after this measurement, an invasive reference reading is taken.By doing this the glucose levels are attributed to the obtained voltage levels which are standardized through a series of experiments and analysis. A suitable and accurate algorithm is hence formulated