Introduction: This study aimed to evaluate the knowledge, attitudes, and behaviors of individuals regarding blood donation.Methods: A questionnaire study was conducted with 644 individuals aged 18 and older who applied to a university hospital outpatient clinic between May 15, 2023, and August 15, 2023. Foreign nationals under the age of 18 were excluded from the study. The first six questions of the questionnaire were about sociodemographic characteristics. The other 28 questions were designed to assess knowledge, attitudes, and behaviors related to blood donation. The data obtained were analyzed with the SPSS 29 program. Categorical data were summarized as frequencies and percentages, and the relationship between variables was evaluated by the chi-square test, post hoc Bonferroni test, and Fisher's Exact Test.Results: Among the participants, 55% (n=354) were married, 57.1% (n=368) were female, 44.4% (n=286) were university graduates, and 24.8% (n=160) were between the ages of 18 and 24. There was a significant relationship between gender and age and individuals' responses to the question about their previous blood donation status. Similarly, there was a significant relationship between the accuracy of answers and educational status and age in the question about the place of blood donation. There was a significant relationship between marital status, educational status, and age and responses to the question about those who were unable to donate blood or diseases that may be caused by blood donation.Conclusion: Individuals' knowledge, attitudes, and behaviors toward blood donation were found to be influenced by sociodemographic factors. Sociodemographic characteristics should be taken into account in activities to encourage blood donation and in the education of the community. It is believed that our study will shed light on future studies in this regard.