Colonization of the stomach with Helicobacter pylori can contribute to the development of gastric ulcers and stomach cancer. The typical treatment course for H pylori infection is a proton pump inhibitor in addition to at least two antibiotics. Increasing resistance to these antibiotics has led to a considerable decline in the eradication rate following treatment over the past several years. The purpose of this study was to assess the rates of resistance to several of the antibiotics commonly used to treat H pylori infection, by investigating a population of patients presenting to a single health care facility in Sudbury, Ontario. Multiple methods were used to assess antibiotic resistance.