Introduction in 2002 the new, 5 - degree classification of chronic renal disease which has been based upon calculation of glomerularfiltration rate (eGFR)--on the one hand took note of the problem of kidney injury and decrease of active nephrons' number which may accompany various renal diseases--on the other--allowed to define the risk factors, which include first of all--hypertension and persistent proteinuria. Chronic renal disease is diagnosed in each clinical case, where a decrease of glomerular filtration rate below 90 ml/min/1.73m2 had occurred with or without kidney injury or when a decrease of glomerular filtration rate maintains for at least 3 months on the level < 60 ml/min/1.73 m2. Delayed diagnosis of chronic kidney disease leads to manifestation of chronic renal failure symptoms and excludes an effective nephroprotective treatment. In the face of a large number of potential causes of chronic renal disease which may be encountered by a pediatrician, all children which are numbered among the high risk group--should have eGFR calculated--initially according to the simplest Schwartz formula. Setting of a diagnosis of chronic renal failure only on the basis of serum creatinine concentration doesn't allow to notice hyper-filtration phenomenon and should not be a daily clinical practice. Fundamental approach of therapeutical management in in children with chronic renal disease is slowing down the disease progression and/or elimination or modification of some risk factors. Each child with diagnosed chronic renal disease should be referred to specialist outpatient pediatric nephrology clinic.