In this study, we aimed to investigate the blood pressure (13P) profile in children with a unilateral functioning solitary kidney (UFSK). A group of 49 patients between the ages of 5 and 18 years, and 30 healthy controls between the ages of 6 and 16 years were investigated. Gender, weight, height and body mass index (BMI) of patients and controls were recorded. BP profile was determined by ambulatory BP monitoring (ABPM.). We have observed a higher risk of hypertension compared with healthy children. Also, masked hypertension is more frequently in the patients group and white-coat hypertension was observed in the control group. The mean night-time systolic BP (SBP) load (p = 0.01) and 24-h diastolic BP (DBP) load (p = 0.008) of children with multicystic dysplastic kidney (MCDK) was significantly higher than the healthy group. The mean night-time SBP load (p = 0.001) of children with unilateral renal agenesis (URA) and 24-h DBP load (p - 0.003) of children with unilateral atrophic or hypoplastic kidney were significantly higher than healthy group. We showed that the children with a solitary kidney had increased risk of hypertension. ABPM reflects the BP profile more precisely than casual BP measurement and it can be used to evaluate white-coat and masked hypertension in children with a solitary kidney.