The aetiology of acute appendicitis remains uncertain. H. pylori is viable outside the gastroduodenum, however its pathological role outside this area has not been fully investigated. Ten consecutive patients with a histological diagnosis of acute appendicitis were investigated for H. pylori status by serology, and by culture, histology, and polymerase chain reaction (PCR) analysis of the appendiceal specimens. One patient had positive serology for H. pylori, however PCR analysis was negative. Culture failed to reveal H. pylori colonies. Histology in 5 cases did reveal organisms with a morphological appearance of H. pylori, but PCR analysis confirmed that H. pylori was not present. Using a variety of methods, with PCR acting as the 'gold standard', we have shown that H. pylori is not associated with acute appendicitis.