Previous research on H1N1 ("Swine flu") has demonstrated that although the public reported concern about H1N1, knowledge levels were low, as were reports of behavioural changes aimed at minimising the spread of H1N1. The current study had two main aims; (i) to ascertain levels of state anxiety and knowledge about H1N1, and (ii) to examine if illness perceptions predict anxiety about H1N1, perceived risk of contracting H1N1, and knowledge about H1N1. The study was cross-sectional in design, and involved 235 participants (100 males, 135 females, mean age 22.48 years) completing self-report measures of knowledge, anxiety, and perceived risk about H1N1, and illness perceptions (BIPQ). Analyses revealed low levels of knowledge about H1N1, 37.4% of participants could not identify any of the causes of H1N1. Correlation and multiple regression analyses demonstrated that illness perceptions were associated with responses to H1N1, with negative illness perceptions predicting state anxiety (β = 0.498, p < 0.01) and perceived risk of contracting H1N1 (β = 0.346, p < 0.01). In addition, females (M = 10.07, SD = 2.68) were found to have higher levels of knowledge about H1N1, compared to males (M = 8.29, SD = 2.65), t(233) = -5.08, p < 0.001. These findings suggest low levels of knowledge about the causes, symptoms and possible preventive measures associated with H1N1. In addition, the current study points to a key role for illness perceptions in predicting psychological responses to H1N1.