Hypertension (HTN) is commonly encountered following kidney transplantation (KT). Some of the responsible factors are transplant medications, allograft dysfunction, allograft renal artery stenosis and the primary renal diseases. HTN is a cause of decreased allograft survival. In this study, prevalence of HTN is evaluated in children following KT. Clinical records of all children who had been transplanted in our center since 1992 were evaluated in their last referral to their in-charge nephrologist. HTN was defined by using new guidelines (JNC7) and children were considered hypertensive if they were on antihypertensive medications and or had blood pressure (BP) >90th percentile for age, height, and sex. From 216 children who were ≤ 19 years old when kidney transplanted (1992 to 2007), 138 children were followed by pediatric nephrologists for mean of 59.2±39 months. There were 79 (57.2%) boys with male to female ratio of 1.33. The age range at time of KT was 3-19 years with a Mean ± SD of 13.6±3.5. The minimum weight was 10 kg. Donor ages were 1 to 52 years with a mean of 24.6±12.5 with 41 parents, 9 siblings and other relatives, 67 deceased and 21 unrelated. Their Primary renal diseases consisted of glomerular diseases, hereditary diseases, reflux-obstruction dysplasia, stone and unknown in 26 (19%), 47 (34%), 58 (42%), 2 (1.5%) and 5 (3.5%) respectively. The mode of dialysis before transplantation was hemodialysis in the majority of cases (85.5%) and preemptive transplantation was done in 12.1%. HTN was observed in 76 children (55%). Regarding primary renal diseases, HTN occurred in 16(61.5%), 26 (55.3%) and 31(53.44%) of the patients in glomerular diseases, hereditary diseases and reflux-obstruction group respectively. In 29 patients, more than one drug was used to control BP. Twenty one (67.7%) of 32 patients with a follow-up period of 6-36months, 27(60%) of 45 patients with follow-up period of 37-72 months and 29(47.5%) of 61 with follow-up period of more than 72 months were hypertensive. In conclusion, Hypertension is very common following kidney transplantation in children and the rate of HTN is inversely related to duration of follow-up.