Helicobacter pylori (H. pylori) bacterium is responsible for the development of various diseases of the upper gastrointestinal tract, including cancer of the stomach. Infection can be very resilient and can last a lifetime. Therefore early detection and treatment of this infection is of great importance. There are several different methods of diagnosis which can be used to detect the presence of this bacterium in the human stomach and to monitor the success of antimicrobial therapy. In order to evaluate the diagnostic utility of testing for the determination of H. pylori antigen in stool we collected data on 100 patients aged 10 to 85 years. We assessed the diagnostic values (sensitivity, specificity, positive and negative predictive value and accuracy) qualitative and quantitative methods for the determination of H. pylori antigen in stool compared with the urea breath test and the link between the values of qualitative determination of H. pylori antigen in stool and the concentration of H. pylori antigen in stool. With this research, we wanted to determine whether the method of determining the H. pylori antigen in stool can replace the urea breath test used so far. On our group of patients, we found 90,32% sensitivity and 81,40% specificity of ImmunoCard STAT! HpSA test for the qualitative determination of H. pylori antigen in stool. Its positive predictive value was 77,78%, negative predictive value of 92,11% and accuracy 85,14%. The sensitivity of Helicobacter Pylori DRG® Ag (stool) ELISA test for the determination of H. pylori antigen in stool is 87,10% and specificity 97,67%, positive predictive value is 96,43%, negative predictive value of 91,30% and accuracy 93,24%. In the qualitative test we calculated cut-off value of 0,910 μg/l. With this research we demonstrated that both tests intended for determining the presence of H. pylori antigen in stool, are comparable with the urea breath test, and can therefore be used as a cheaper substitute in assessment of the effectiveness of antimicrobial therapy against H. pylori. Tests are also comparable with each other; however, the qualitative test serves only for the detection of bacteria, whereas the quantitative test also determines the amount of bacterium present.