Carbon-14 ( 14 C) is present in the environment and in all organic materials and behaves in the environment in the same manner as other carbon isotopes. In medicine, 14 C can be injected to study abnormalities of metabolism that underlie diabetes, gout, anaemia and acromegaly (adult gigantism), and for diagnosis of Helicobacter pylori (H. pylori). The discovery H. pylori by Warren and Marshall in 1982 changed the approach to treat peptic ulcer disease (PUD). Since then H. pylori has been the focus of clinical research and debate. The causal relationship between H. pylori infection and chronic gastritis is well established. H. pylori infection is one of the most common human infections worldwide. This organism has been shown to infect over half of the world's population. This article presents the application of 14 C Urea Breath Test ( 14 C UBT) for the diagnosis of the H. pylori bacteria which present in the stomach and duodenum. 14 C UBT relies on the urease activity of H. pylori to detect the presence of active infection. 14 C UBT has proved to be one of the most accurate methods for assessing H. pylori status. The ionizing radiation dose involved in this test is extremely low, much lower than the radiation dose due to natural sources. 209 samples collected from both symptomatic and non-symptomatic persons of Dakhina Kannada District, Karnataka were analysed and the results with discussion are presented in this paper.