HT is a frequent cardiovascular risk factor in liver transplant recipients. However, there are only few studies in the literature regarding the risk of HT in liver transplanted children. The aim of this study was to assess the 24 h BP profiles of liver transplanted patients and to compare the results with healthy children. ABPM was performed on 20 liver transplanted patients and 27 healthy children aged 7.1 ± 4.8 and 8.5 ± 2.9 yr, respectively. HT was defined as SDS > 1.64 (i.e., >95th percentile) adjusted for gender and height. The mean duration of post-transplant follow-up was 32 ± 19 months. Six (30%) patients were found to be hypertensive. The physiological nocturnal BP fall was attenuated significantly in the study group for diastolic BP (11.5 ± 6.1 mmHg vs. 17.7 ± 7.1 mmHg, p = 0.006). Specifically, the number of patients with high nighttime systolic and diastolic BP SDS (p = 0.02 and p = 0.004, respectively) as well as elevated nighttime systolic (p = 0.03) and diastolic (p = 0.003) BPLs was found to be significantly higher than those in the controls. Alteration of the “normal” circadian rhythm is very frequent in liver transplant recipients. Thus, it is recommended to perform ABPM on all liver transplanted children not to underdiagnose HT.