Environmental Sensitivity (ES) is defined as the ability to register and process external stimuli. Different individuals process these stimuli in varied ways, which can lead to both negative and positive consequences. This study aimed to adapt the Highly Sensitive Child Scale (HSCS) to Portuguese and evaluate its psychometric properties in a Brazilian population. Data were collected from 623 young people aged 8 to 13 years (49.6% female, 68.0% from the Southeast region, and 63.0% white). Confirmatory factor analyses indicated an adequate structure for the three correlated factors of the original scale: aesthetic sensitivity (AES), ease of excitation (EOE), and low sensory threshold (LST). The scale correlated with the factors of the Behavioral Inhibition and Activation Scale (BIS/BAS), consistent with the original validation. Female participants had higher mean scores than males for AES and EOE, but not for LST. Configural and metric invariance with respect to gender was observed; however, scalar invariance was not. A latent class analysis identified three groups among the participants: low (12.1%), moderate (41.2%), and high (46.1%) sensitivity. The results indicate good psychometric qualities and the suitability of the translated scale for application in a Brazilian population.