The value of a two point analysis (double sample) 14C-urea breath test in diagnosing Helicobacterpylori (HP) infection in patients with suspected acid peptic disease has been studied and compared to histology and to a rapid agar plate urease test in 76 patients. Using the histological finding of HP as the gold standard, the 14C-breath test was positive in 59 of the 61 histologically confirmed infected patients and in 3 of the 15 noninfected ones, giving a sensitivity of 97% and specificity of 80%. In 12 patients, a smaller dose of 3 μCi 14C-urea was used. The results correlated well with those in whom the higher dose of 10 μCi was used. We conclude that a two point 14C-urea breath test with analysis at 5 and 15 min is effective in diagnosing HP infection thus obviating the need for endoscopy and biops