Percutaneous renal biopsy (PRB) is an integral part of the clinical practice of nephrology. It is a safe and effective tool in the diagnosis of glomerular, vascular and tubulointerstitial diseases of the kidney, providing information that is invaluable in prognosis and patient management. PRB of native kidneys was performed by nephrologists in 249 patients consecutively from May 1997 through May 2005 at the Department of Nephrology, Dubrava University Hospital, Zagreb, Croatia. The biopsy was done using continuous ultrasound guidance and a 16-gauge biopsy needle (Tru-Cut) in an automated gun (Biopty Bard). All biopsies were processed for light, immunofluorescence and electron microscopy. We analyzed yield of diagnostically useful material and frequency of postbiopsy complication. Adequate tissue for histologic diagnosis was obtained in 95% of the procedures. The mean glomerular yield was 11.9 glomeruli. The main indications for renal biopsy were nephrotic syndrome (33%) hematuria and/or non-nephrotic proteinuria (13%) and renal failure (12%). The dominant types of primary glomerulonephritis (GN) were focal segmental glomerulosclerosis (FSGS) in 27%, mesangioproliferative in 13%, IgA nephropathy in 11%, membranous GN in 11%, membranoproliferative GN in 5%, crescentic GN--5%, and minimal change disease (MCD) in 3% of cases. The most frequent complications were perirenal hematoma (clinically asymptomatic) in 3.6%, macrohematuria in 1.2%; bleeding complications requiring blood transfusion and/or therapeutic radiologic intervention were not seen, and surgical procedure was indicated in one (0.4%) patient. We conclude that real-time ultrasound is a safe, accurate method in localizing the kidney for percutaneous renal biopsy and a very effective approach for early detection of perirenal hematoma and other potential postbiopsy complications. The present data are an important contribution to the epidemiology of renal disease, highlighting significant epidemiological differences in European countries, particularly a higher incidence of FSGS as a proportion of primary GN in our population. This report represents a basis for the future Croatian Registry of Renal Biopsies and is intended to serve as a source of information for further studies.