The aims of this study were to evaluate the attitudes towards H1N1 vaccination and to determine the safety and side effects following 2009 pandemic influenza A (H1N1) vaccination. Pandemic influenza vaccine had been administered to the healthcare personnel in our research and training hospital in December 2009. The rate being vaccinated was established as 40% (800/2000). Four months following vaccination, the opinions about vaccination were asked to the healthcare workers, and also side effects were questioned to the vaccinated group. Two different questionnaires (for vaccinated and unvaccinated subjects) were delivered to the volunteers who agreed to participate in the study. Demographic features, reasons related to being vaccinated or not, were questioned. The vaccinated group was also questioned for the presence of chronic diseases, previous vaccinations (pandemic/seasonal influenza), local or systemic reactions that develop after vaccination. A total of 332 volunteers participated in the questionnaire. Of them 247 (74.4%) were vaccinated and 85 (25.6%) were unvaccinated. Male/female ratio of the participants was 1.2, and 55.7% of them were older than 30-year-old. Most of the participants (82.8%) were highly educated (high school and faculty-graduated). Vaccination rates were found statistically significant in advanced age group compared to young adults (p= 0.042); in male gender compared to females (p= 0.001) and in parents compared to subjects who didn t have children (p= 0.021). Vaccination rates were observed to be higher (57.5%) in non-medical staff (cleaning employers, administrative personnel, etc.) than the physicians (29.1%) and nurses (13.4%), and the rate was also high (54.7%) in personnel who worked in intensive care units, emergency department and administrative units than the personnel who worked in the clinics of internal medicine (22.3%) and surgery (23.1%) (p= 0.001). The most important causes of rejecting vaccination were being afraid of the side effects (69.4%) and not believing the effectiveness of the vaccine (56.4%). The leading causes of accepting vaccination were worries about infecting their family (60.3%) and being in a risk group (54.3%). After vaccination, local reactions (pain, swelling and redness at the vaccination site) were described in 43.3% and systemic reactions (weakness, fatigue, muscle aches, influenza-like symptoms, etc.) were described in 43.7% of the subjects. Severe side effects such as vasculitis, neuritis, encephalomyelitis, Guillian-Barre syndrome and anaphylactic reaction were not observed in any of the vaccinated cases. It was detected that worries about the safety of vaccine had negative impact for vaccination. Since no serious side effects were detected related to vaccination, it was concluded that the vaccine was safe. In spite of the scientific proofs, negative concerns about the safety of the vaccines can unfavorably affect the vaccination campaigns and can jeopardize efforts of influenza control. As a result, data collection systems about the safety and side effects of the vaccine all over the country and regular reports about these data may moreefficiently guide vaccination programs in the future.