The estimates risks and benefits of the percutaneous kidney biopsy have been reported mainly from retrospective studies. So far no prospective multicentre studies has been designed to identify rates of biopsy related complications. The aim of this prospective multicentre study was to evaluate safety and complication events related to biopsies on native kidney in Italy.

Kidney biopsies performed in 54 italian nephrology centres from 2012 to 2020 were included.

Primary outcome of the study was any major complication, such as haemoglobin decrease more than 2 g/dL, macroematuria, gross ematoma, blood transfusion, artero-venous fistula, invasive intervention, pain, symptomatic hypotension, and/or rapid serum creatinine increase.

Centre and individual patient risk predictors were analysed using multivariate logistic regression analysis.

Inclusion Criteria:

• adult or pediatric patients with a kidney disease
• informed Consent

Exclusion Criteria:

• patient with a transplanted kidney

Data collection of native kidney biopsies was centralized and takes place via Web by means of an ad hoc web-database linked to the National Italian Renal Biopsy Registry (http://www.irrb.net/). As this is an observational study, we collect information already available and typical of usual clinical practice. There are no particular requested exams.