BACKGROUND To analyze the relationship between early-life indicators, blood pressure (BP), and arterial stiffness in childhood, in three samples with different bio-cultural characteristics. METHODS The total sample included 520 schoolchildren 9–10 years of age from Madrid (Spain), Vitória (Brazil), and Luanda (Angola). Height and weight, BP, and carotid-femoral pulse wave velocity (cf-PWV) were measured, all by one observer in each site, and body mass index (BMI) was calculated. Birth weight, gestational age, type of feeding, and age at weaning were extracted from official health cards. Data were analyzed by multiple linear regression models. RESULTS No significant differences were observed in systolic blood pressure (SBP) and diastolic blood pressure (DBP) among the samples (P = 0.107 and P = 0.808). Luanda showed the higher cf-PWV (5.7 m/s), followed by Vitória (5.3 m/s) and Madrid (4.9 m/s; P < 0.001). Explanatory factors for the observed variability in SBP, DBP, and cf-PWV, obtained by means of multiple linear regression models, were different in three samples. BMI showed a positive and significant association with SBP, DBP, and cf-PWV in three samples. In the Angolan sample, in addition to BMI, birth weight was maintained in the explanatory models of SBP and cf-PWV adjusted for BP, with a negative and significant coefficient (−0.019 and −0.019) CONCLUSIONS Higher values of BMI in childhood are related with higher values of cf-PWV, SBP, and DBP in the three samples. Children from Angola showed the highest mean value of cf-PWV, especially those who had lower birth weight, suggesting that worse conditions in fetal life may contribute to increased aortic stiffness in childhood.