Background: Achieving normohydration remains a challenge in haemodialysis (HD) therapy. Estimating dry weight only based on the clinical evaluation may be dangerous, especially in case of volume independent hypertension. Bioimpedance spectroscopy (BIS) and inferior vena cava diameter (IVCD) are new simple and reliable methods for probing dry weight. Aim: The aim of this work was to assess the hydration status of children on HD with the weight and blood pressure (BP) and comparing it with BIS and IVCD. Methods: from Center of Pediatric Nephrology and Transplantation, Abu El-Rish Hospital, Cairo University, thirty patients on regular HD (10 males& 20 females) were enrolled. We used three different methods of evaluation: the clinical parameters ( including weight & BP ) ( pre, during and post HD ), IVCD ( pre, during and post HD) and BIS data ( including extracellular water ( ECW ) and overhydration ( OH ) ) ( pre and post HD ) on three phases. Results: There was a highly significant reduction in weight, ultrafiltration (UF), BP, IVCD and BIS post HD ( P