Since 2001 there has been a steadily increasing awareness of discrimination against Muslims based on their religion. Despite the widespread use of the neologism Islamophobia to refer to this phenomenon, this term has been harshly criticized for confounding prejudiced views of Muslims with a legitimate critique of Muslim practices based on secular grounds. In the current research a scale was developed to differentiate Islamoprejudice (based on the influential Islamophobia definition of the British Runnymede Trust) and Secular Critique of Islam. Across two studies, Islamoprejudice was related to explicit and implicit prejudice, right-wing authoritarianism, and social dominance orientation whereas Secular Critique was unrelated to any forms of prejudice but negatively related to religiosity and authoritarianism. The two scales were mostly independent or only moderately related. Importantly, the new Islamoprejudice scale outperformed all other scales in predicting actual opposition versus support for a heatedly debated, newly built mosque. These results demonstrate the necessity to differentiate between Islamoprejudice and Secular Critique in future research on attitudes towards Islam.