Objective: The aim of this study was to evaluate the relationship of local intrarenal renin angiotensin system (RAS) with proteinuria in patients with renal AA amyloidosis. Methods: Thirty-two patients with renal AA amyloidosis (19 male, mean age: 45 +/- 13 years) and sixteen healthy controls (5 male, mean age: 32 +/- 5 years) were included in this study. Spot urine samples were obtained to measure urinary angiotensinogen (AGT) using human AGT-ELISA, urinary creatinine and protein levels. Logarithmic transformations of urinary AGT-creatinine ratio log(UAGT/Ucre) and urinary protein-to-creatinine ratio (UPCR) were done to obtain the normal distributions of these parameters. Results: Log(UAGT/UCre) was significantly higher in patients compared with the controls (1.88 +/- 0.92 mu g/g vs. 1.25 +/- 0.70 mu g/g; p = 0.023). Importantly a significantly positive correlation was found between log(UAGT/Ucre) and logUPCR in patients (r = 0.595, p = 0.006). Conclusions: Urinary AGT levels are higher in renal AA amyloidosis patients than in controls. Also, there is a significant positive correlation between urinary AGT and proteinuria in renal AA amyloidosis.