An instrument comprising sixteen original vignettes was field tested to gather evidence of their validity and reliability in measuring heterosexist attitudes among educators. Two-hundred seventy pre-service and in-service teachers and counselors completed the instrument. The items were analyzed using statistical methods informed from Classical Test Theory, Item Response Theory and exploratory and confirmatory factor analysis. Overall item functioning was shown to be moderate, and several poor functioning items were dropped. The results of the confirmatory factor analysis indicated that a three factor model fit the data well. Thus, heterosexist attitudes can be seen as falling along three dimensions: attitudes that ostracize LGB students from school, attitudes that prescribe LGB students to specific patterns of behavior, and attitudes that trivialize the discrimination faced by LGB students. Significant positive correlations were found with the prescribe and ostracize scales and an existing scale that has been established to measure homophobia. Limitations and future directions are discussed.