Elevated body mass index (BMI) has been associated with cardiac changes, such as higher epicardial adipose tissue (EAT) thickness. This fat has been identified as a predictive factor of cardiovascular diseases during adulthood. However, few studies have tested the association of multiple cardiovascular risk factors (high weight or blood pressure) with EAT in adolescents and children. Therefore, the main objective of this current research was to determine the impact of BMI, overweight, obesity, and blood pressure on EAT thickness in children. A descriptive cross-sectional study focused on elementary and high school students aged 6-16 years was carried out by utilizing diverse measurements and instruments, such as echocardiography. EAT thickness (N = 228) was linked to sex (more predominant in boys 2.3 ± 0.6; p = 0.044), obesity (2.3 ± 0.6; p < 0.001), and hypertension (2.6 ± 0.6; p = 0.036). The logistic regression indicated that age, sex, and BMI seemed to be more relevant factors in EAT thickness in children (adjusted R square = 0.22; p < 0.001). This paper examined the associations of sex, age, and cardiovascular risk factors (arthrometric measures and blood pressure) with EAT thickness, indicating that it is necessary to assess whether the findings are associated with future events. Excessive weight gain and blood pressure in the early stages of life have been associated with adipose tissue. This increase in weight and blood pressure has been attributed to alterations in the epicardial adipose tissue linked to anthropometric markers in adults, but no related study has been implemented in Spanish children. This study revealed how higher epicardial adipose tissue is linked to body mass index, other anthropometric parameters, and blood pressure in Spanish children. These measurements are related to high epicardial adipose tissue thickness, which in early stages does not imply pathology but increases the risk of developing cardiovascular diseases.