A correlation between delta over baseline (DOB) values of the [(13)C]urea breath test (UBT) and Helicobacter pylori clarithromycin resistance has been reported, suggesting a possible predictive role of UBT in therapeutic outcome. However, available data are limited and conflicting. This study aimed to clarify this issue, assessing the possible relationship between H. pylori resistance towards different antibiotics (clarithromycin, metronidazole and levofloxacin) and UBT values. The data showed similar DOB values between susceptible and resistant strains for clarithromycin (46.9+/-32.3 vs 45.7+/-30.6; P=0.8), metronidazole (46.4+/-29.6 vs 47.4+/-37.9; P=0.8), and levofloxacin (45.0+/-30.2 vs 54.2+/-38.4; P=0.08). Likewise, comparable DOB values were observed between susceptible and multidrug-resistant strains (45.4+/-29.6 vs 54.8+/-44.8; P=0.1). In conclusion, our data failed to find a significant correlation between UBT values and H. pylori antibiotic resistance.