Helicobacter pylori is currently implicated in the pathogenesis of various of digestive tract disorders and also a risk factor in gastric carcinomas. H. pylori infection is detected by various invasive & non invasive methods and each method has its own pits & falls. Out of all the techniques PCR is considered to be most rapid, accurate and sensitive method. The present study is an attempt to evaluate and compare the efficiency of all invasive techniques considering PCR as a Gold standard test. As part of long-term clinical studies, the PCR assay has the advantage of detecting low numbers of bacteria after successful or unsuccessful therapy or prior to relapse and will, we hope, permit the evaluation of the efficacy of various antimicrobial regimens.