Research Findings: Empathy, or the ability to understand what others are thinking or feeling, can be observed in early developmental stages. The purpose of this study was to validate the Spanish version of the Empathy Questionnaire (EmQue) and examine its longitudinal measurement invariance (LMI) at 2 time points. Parents of 103 children completed the EmQue when their children were 3 (M = 41.76) and 4 (M = 51.65) years old. Confirmatory factor analyses revealed that Grazzani, Ornaghi, Pepe, Brazzelli and Rieffe's (2016) 3-factor model of emotional contagion (EC), attention to others' feelings, and prosocial actions (PA) presented the best fit indices at both time points (Time 1: CFI = 0.931, TLI = 0.914, and RMSEA = 0.070; Time 2: CFI = 0.941, TLI = 0.935, and RMSEA = 0.064). Moreover, preliminary evidence was obtained for the LMI of this model. PA scores increased over time. Score reliability ranged from 0.60 (EC) to 0.83 (PA). Positive correlations were found between PA and emotional regulation at each time point and across time. Practice or Policy: The great relevance of empathy and prosocial behavior in academic achievement and psychological adjustment justifies the development of reliable instruments to evaluate these constructs from early ages.