The Emotion Understanding Assessment (EUA) is based on a theoretical model of recognizing emotion expressions and reasoning about situation-based, desire-based, and belief-based emotions. While research has noted that emotion understanding predicts current and future social and academic functioning, little is known about the psychometric properties of the EUA. This research sought to test the EUA factor structure and measurement invariance across gender, across language (English and Spanish speakers), and over time (24 weeks) in 281 preschoolers attending Head Start. Results indicated that a two-factor model of emotion expression recognition and emotional perspective taking of the EUA fit the data for the total sample, for each group (gender and language), and at each time point. Furthermore, configural and scalar invariance of the EUA was demonstrated across gender, language, and time. These results offer support that the EUA is assessing emotion expression recognition and emotional perspective taking constructs equivalently in boy, girls, Spanish and English speakers, and over time. Examination of latent means across groups and time indicate no differences in emotion understanding based on gender or language or over the 24-week time frame in this sample of preschoolers attending Head Start.