In a study of 63 adult patients, subjected to upper gastrointestinal endoscopy due to gastrointestinal disorders or indigestion, gastric mucous biopsies were taken in order to realize a rapid urease test, conventional histology, selective culture for H. pylori and to determine susceptibility of bacterial isolates to clarithromycin using Kirby-Bauer disk diffusion technique. The percentage of H. pylori recuperation (positive culture) was 73%. A sensitivity of 66% was determined for the culture, and a specificity of 100% was also determined. A prevalent primary resistance to clarithromycin of 15% was observed. Significant differences were not observed due to gender, age, endoscopic or histological diagnoses among the patients with sensitive isolates or resistance to antibiotics.