To assess factors associated with prehypertension and hypertension among children in North Africa.An epidemiological observational, school- and college-based study among 3562 healthy children and adolescents to assess factors associated with blood pressure categories (normal, prehypertensive, hypertensive), including perinatal (gestational age, birth weight, breastfeeding) and current lifestyle characteristics (body mass index, time spent watching a screen and time spent exercising).Prevalence of hypertension increased with age from 8.7% between 6-10 years to 14.7% between 11-15 years, and 15.6% above 15 years. Prevalence of prehypertension and hypertension increased with body mass index from 9.9% and 11.5% among children not overweight to 15.6% (RR 1.58, 95% CI 1.24-2.02, P<0.001) and 17.2% (RR 1.50, 95% CI 1.22-1.85, P<0.001) among those overweight and to 26.8% (RR 2.72, 95% CI 2.04-3.64, P<0.01) and 32.3% (RR 2.82, 95% CI 2.27-3.50, P<0.01) among obese children. There was a trend of association of prehypertension with the time spent watching Television, internet and electronic games. Children whose mother or father had a history of hypertension had a trend to be prehypertensive or hypertensive. A parental hypertension was found in 33.6% of normotensive, 38.2% of prehypertensive, and 42.6% of hypertensive children (P=0.05). Children with prehypertension or hypertension were more likely to have a diabetic father or mother (22.8% and 22.6% vs 15.8%, respectively, P=0.01). Also, prehypertension and hypertension were associated with shorter gestational age, early birth, reduced birth weight, and shorter breastfeeding.Prehypertension and hypertension have a high prevalence among children in North Africa. They are associated with overweight, obesity, diabetes, a shorter gestational age, a lower birth weight and a shorter breastfeeding.