OBJEc TIVE: Amyloidosis is a chronic disease associated with proteinuria and can progressto renal failure. The diagnosis and treatment of the underlying cause is therefore important. In thisstudy at a university hospital, the diagnosis of amyloidosis patients with renal biopsies was evaluatedretrospectively.MATERIAL and METhODS: 69 (42 males, 27 females, mean age: 51.7 ± 14.8 years) patientswere diagnosed with amyloidosis with renal biopsy. Indications for biopsy was nephrotic syndromein 42 patients (60.9%), nephritic syndrome in 27 (39.1%) and renal dysfunction with proteinuria in 31(44.9%).RESULTS: The most common causes of secondary amyloidosis were Familial Mediterranean Feverin 17 of the 62 patients, chronic infammatory diseases in 17 patients and chronic infection in 13patients. No cause was determined in 12 patients. Multiple myeloma was present in 5 patients withprimary amyloidosis. At the time of diagnosis with amyloidosis, 19 patients were stage 1, 15 stage 2, 5stage 3A, 12 stage 3B, 10 stage 4 and 8 stage 5. The baseline hemoglobin, serum albumin, creatinine,sodium, potassium, calcium, phosphorus, AST, ALT, PTH, SAA, CRP levels, average daily urinaryprotein excretion and baseline GFR values were not signifcantly different in primary and secondaryamyloidosis patients. The treatment was medical in 62.3% of the patients, dialysis in 31.9% and renaltransplantation in 5.8%.c ON cLUSION: The reliability of renal biopsy in the diagnosis of amyloidosis is high. However, genetic studies for the diagnosis of idiopathiccases and special histological staining methods should be considered.KEY wORDS: Amyloidosis, Kidney biopsy, Proteinuria, Chronic kidney disease