ObjectivesThis study assessed the prevalence and changes of human immunodeficiency virus (HIV) knowledge and stigmatizing attitudes in 2006, 2008, and 2011.MethodsThree cross-sectional surveys were conducted in 2006, 2008, and 2011. A cross-sectional sample of high school students in Seoul, South Korea was targeted. A self-administered questionnaire measuring general and transmission and discriminatory attitudes was used.ResultsMisconceptions about casual contact were widespread, even though the proportion responding incorrectly decreased significantly over the 5-year period. The respondents in all surveys displayed a high level of discrimination against those with HIV/AIDS in some situations, particularly in the idea of HIV/AIDS making the respondent feel disgusted (63.3% in 2006, 57.5% in 2008, and 52.6% in 2011), avoiding sitting with people with HIV/AIDS (50.6% in 2006, 50.5% in 2008, and 48.5% in 2011), and blaming those with HIV for becoming infected (46.6% in 2006, 42.8% in 2008, and 43.0% in 2011). Even though respondents had a high level of stigmatizing attitudes, the survey showed that the stigma has declined over the 5-year period.ConclusionThe survey results showed that public health policy should recognize that HIV stigmatizing attitudes persist in Korea. This finding has implications for the development of intervention programs focusing on reducing the levels of discrimination.