Triple-therapy (a proton-pump inhibitor and 2 antibiotics) is used in eradicating Helicobacter pylori but is problematic in regard to compliance and side effects. In the literature, these are often mentioned but not appropriately assessed. Objectives: 1) To assess the degree of compliance and the presence of side effects in a triple-therapy regimen with omeprazole (O), amoxycillin (A), and tinidazole (T); 2) In cases of severe sensitization, to use specific immunologic assays (macrophage migration inhibition factor (MIF), mast cell degranulation (MCD) tests) to detect the responsible drug. Methods; 52 patients (29 men) - 35 with non-ulcer dyspepsia (NUD) and 19 with peptic disease (9 - duodenal ulcer; 6 - duodenitis; 2 - gastric ulcer) were compared. The patients were fully instructed as to a 2-week regimen of treatment (0 - 20 mg × 2/day, A - 500 mg × 4/day; T, 500 mg × 2/day, to be added from day 5) and received a form for registering intake and side effects. Results: Side effects were absent in 36 patients (69%) ; minor in 9 (17%); moderate in 2 (4%) and severe in 5 (10%). In the latter (all women), they included urticaria (1), leg edema (1), skin eruption (2) and oral paresthesia (1). Testing was successful in detecting the cause of the sensitivity reactions, particularly the 0 in the 2 first events. Conclusions: 1) Compliance was excellent despite the complexity of the treatment regimen; 2) In most cases, side effects were minor. In cases of sensitivity, immunological tests proved useful in detecting the culprit, especially O, which may be replaced by lansoprazole in further therapy.