LITTLE IS KNOWN ABOUT BLOOD PRESSURE LEVELS and the extent of high blood pressure in Hispanic children and adolescents, especially in groups other than Mexican Americans. The authors of this study investigated the levels of systolic blood pressure (SBP) and diastolic blood pressure (DBP) and the extent of high blood pressure among Mexican-American, Cuban-American, and mainland Puerto Rican children and adolescents who participated in the Hispanic Health and Nutrition Examination Survey (HHANES). Very few children and adolescents in these three Hispanic groups had high normal or high blood pressure. Puerto Rican children had significantly lower DBP than Mexican-American (2.4 mmHg) and Cuban-American (1.8 mmHg) children. Their SBP was also lower (1.7 mmHg) than that of Cuban-American children. These findings should be interpreted cautiously, however, since a significant observer effect was also found in this study. Correlates of blood pressure in children in all three Hispanic groups were consistent with those found in studies of other ethnic groups. Age, body mass index, and pulse rate were significant predictors of both SBP and DBP (P less than 0.05). Gender was an important predictor of SBP but not DBP. Socioeconomic and cultural factors were not significant predictors of blood pressure in these Hispanic groups.