PURPOSE: To evaluate the diagnostic yield and complications of percutaneous ultrasound-guided renal biopsyusing a biopsy gun in patients with diffuse renal disease. MATERIALS AND METHODS: Using an automated biopsy gunmounted with a 16G needle, biopsies were performed on 90 patients with diffuse renal disease. In a total of 95biopsies, diagnostic yield, the mean number of glomeruli and frequency of complication were retrospectivelyanalysed. RESULTS: Tissue adequate for histological diagnosis was obtained in 92% of procedures. Mean glomerularyield was 8.3, and complications were seen in 26% of the procedures, 25% of these were minor, and 1% were major. CONCLUSION: For the diagnosis of diffuse renal disease, utrasound-guided percutaneous renal biopsy using anautomated biopsy gun is accurate and safe.