Background and Aims Hepatocyte nuclear factor 1 gene (HNF1B) encodes for HNF-1ß, a transcription factor that is expressed early in embryonic development and plays a key role for tissue-specific regulations of gene expression in various organs such as the kidneys, urogenital tract, liver, biliary ducts and pancreas. HNF1B disease (MIM 137920) is recognized to represent an autosomal dominant syndromal disorder comprising variable phenotype with renal and extrarenal manifestations. Renal phenotype in HNF1B nephropathy is highly heterogeneous. The aim of the study was to evaluate the clinical characteristics of renal involvement in children with genetically proven HNF1B nephropathy. Method Five children (2M/3F) from unrelated families with heterozygous HNF1β mutations and kidney disorders were examined. We evaluated serum levels of electrolytes, magnesium (Mg), phosphorus (P), uric acid, acid-base composition; urinary excretion of Ca, P, creatinine (Cr); fractional excretion (FE) of Mg, urate (Ur), Na, K; tubular maximum phosphate reabsorption per GFR (TmP/GFR), and urinary β-2 microglobulin. Molecular genetic analysis was performed using by next generation sequencing. Results Cortical or medullary bilateral renal cysts were detected in all five children with HNF1B nephropathy. Kidney hypoplasia, medullary nephrocalcinosis, and low-grade proteinuria ( Conclusion The present study demonstrates that patients with HNF1B-associated disease had wide spectrum of renal involvement. The most prevalent features of HNF1B nephropathy in our children were bilateral renal cysts, defects of proximal tubular function with wasting of electrolytes and progression to CKD stage 2-3 at early age.