Aim: The aim of the present study was to compare the seroprevalence of pandemic H1N1 IgG antibodies between health care workers and patients presenting with upper airway symptoms suggestive of H1N1 influenza infection who are admitted to the outpatient clinics during pandemic H1N1 influenza infection.Material and Methods: The present study comprised 82 subjects unvaccinated with influenza A (H1N1) vaccination, including 53 health care workers (33 females, 20 males, 15 doctors; median age: 38 years), 16 nurses (median age: 26.5 years), 22 auxiliary health care workers (median age: 32 years), and 29 outpatients (14 females, 15 males; median age: 38 years). The presence of symptoms suggestive of pandemic influenza infection was questioned in the health care providers and outpatients. Serum H1N1 IgG antibody levels were determined in the health care workers and outpatients using the ELISA method. The statistical analyses were performed using the SPSS software package. ANOVA (analysis of variance) was used to evaluate the significance of difference between the groups, and the Kruskal-Wallis test was used to evaluate the significance of difference in terms of median values. The nominal variables were analyzed using Pearson's chi-square test or Fisher's exact test. A p value of < 0.05 was considered statistically significant. Results: The seroprevalence of H1N1 IgG antibody positivity for health care workers and outpatients were %43.3 and %6.9, respectively. H1N1 IgG antibody seropositivity did not show a significant relation with gender and mean age (p=0.87 and p=0.657, respectively). There was a statistically significant difference between health care workers and outpatients in terms of H1N1 IgG antibody seropositivity (p<0.001). The prevalence of H1N1 IgG antibody seropositivity was significantly higher in health care providers compared to outpatients. The intra-group comparison of health care workers shows a significant difference in terms of H1N1 IgG antibody positivity. The prevalence of H1N1 IgG antibody positivity among the doctors was higher compared to nurses and auxiliary health care workers (p<0.001). Conclusion: Exposure to the H1N1 virus and the prevalence of the H1N1 antibody positivity among health care workers during pandemic influenza infection was higher compared to outpatients presenting with upper airway symptoms suggestive of an influenza infection. Therefore, health care workers who are at risk of acquiring influenza influenza infection encouraged through training about immunization.