Objective: Because of limited resources, the approach in Thailand is to eradicate Helicobacter pylori (H. Pylori) infection in every patient with peptic ulcer perforation, but without infectious confirmation because of suspected high infection rates. Only one study reported the incidence of infection in perforated disease in Thailand with limited number of patents. Our aims were to study the prevalence of H. pylori infection in patients with perforation and to explore associated factors. Methods: In a total 136 patients, infection was confirmed by rapid urease testing during post-operative esophagogastroduodenoscopy. The statistical analysis were Fisher’s exact test and multiple logistic regression analysis. Results: The infection rate was 69.6%. Age ≥ 60 years and male were correlated with infection in multivariable analysis (odds ratio: 3.4 and 4.3, p=0.01 and 0.03, respectively). Only age ≥ 60 years was associated with infection in the univariable analysis (odds ratio: 2.7, p=0.02) with an infection rate of 81.5%. Three upper gastrointestinal cancers were also seen. Conclusion: The prevalence of Helicobacter pylori infection in perforated peptic ulcer patients in our study was high. Male patients ≥ 60 years of age appeared to be more prone to infection. The non-documented infection eradication approach may be more justified in older male patients, especially those with multiple comorbidities.