Environmental sensitivity is the ability to perceive, register and process information about the environment, which differs among children and adolescents. The Highly Sensitive Child (HSC) scale has been used to assess environmental sensitivity in youngsters. The HSC scale is a short and 12-item adapted version of the Highly Sensitive Person (HSP) scale. The aim of this pilot study is to transculturally adapt the Highly Sensitive Child (HSC) scale, and to analyze its factorial structure, reliability and validity. First, a transcultural adaptation was conducted by bilingual experts. Second, once the questionnaire was translated, the psychometric properties were analyzed. The Spanish version of the HSC scale was administered to parents answering about information of 141 children between 6 and 10 years old. The Spanish version of the Emotionality, Activity and Sociability Survey (EAS) was also applied. The results of the confirmatory factor analysis confirmed the three-factor structure of sensitivity in our Spanish sample. This structure included the following dimensions: (1) Ease of Excitation (EOE), (2) Low Sensory Threshold (LST), and (3) Aesthetic Sensitivity (AES). Moreover, both Cronbach’s α and McDonald’s ω values indicated that the Spanish version of the HSC scale was a reliable measure of environmental sensitivity, as a general factor of sensitivity (α = 0.84), and even in its three dimensions: EOE (α = 0.86), LST (α = 0.77) and AES (α = 0.73). Finally, the correlations for convergent validity showed positive associations, especially among the three dimensions of SPS and Emotionality (EOE r = 0.351; LST r = 0.274; AES r = 0.259), which was one of the domains of the EAS survey. The pilot study provided interesting results, which showed a reliable and valid replication of the original structure of sensitivity in the Spanish samples.