This study aimed to know the relation between cagA positive Helicobacter pylori (HP) strains and diseases such as gastric and duodenal ulcers and gastric adenocarcinoma. The study included 61 dyspeptic patients from gastrointestinal (GI) endoscopy department patients in Al-Assad university hospital in Lattakia. During upper (GI) endoscopy, gastric biopsy specimens were obtained for Clo-test and histologic examination. Blood was obtained from Clo-test positive patients for serologic tests of HP and cagA. After upper (GI) endoscopy and histologic examination, patients were divided into 4 groups: chronic gastritis (28 patients), gastric ulcer (5 patients), duodenal ulcer (17 patients) and gastric adenocarcinoma (11 patients). CagA antibodies were positive in 68.85% of patients. The difference in the proportion of CagA antibody positive between the four groups was highly significant (P= 0.006). The highest positive proportion was in gastric adenocarcinoma (90.91%) then duodenal ulcer (88.24%) then gastric ulcer (80%), while the lowest positive proportion was in chronic gastritis (46.43%). There was no difference in HP antibody levels between the four groups (P = 0.90) but these levels were significantly higher in cagA+ patients compared to cagA- (P= 0.05). This study found a positive relation between cagA+ and diseases such as peptic ulcer and gastric adenocarcinoma in Syria .