Helicobacter pylori is infective cause of peptic ulcer and a risk factor for gastric carcinoma. The discovery of the bacterial ed to importance of finding a new reliable and inexpensive diagnostic method for detection of infection before and after eradication therapy. Urea breath test is isotope based test. It has become the most specific and sensitive method in detection of Helicobacter pylori infection, therefore many other isotope based tests become popular in diagnostic of gastrointestinal diseases. Because of its simplicity and no need in using endoscopy in the procedure it is very popular in primary diagnosis and in controlling eradication. It is successfully used in diagnostics of Helicobacter pylori and bacteria eradication success testing, where it is one of most reliable diagnostic methods.