The bilateral primary renal lymphoma (PRL) is a rare disease with a high mortality rate (75% within the first year). We report the case of a fifty-three years old women observed in January 2011 for renal colic. Ultrasonography showed hypoechoic lobular formations in the kidney. Blood tests showed: creatinine 1.8 mg/dl, urea 75 mg/dl , Creatinine Clerance 35 ml/m, hemoglobinemia 11 g/dl, with blood cells 8.500/mcL, Albumin 2.8 g/dl, Beta -2 micro - 27.3/mL. Proteinuria was 0.3 g/24 hours. The CT scan showed kidneys with larger dimensions and multiple hypodense areas infiltrating the renal parenchyma with contrast-enhanced low in which kidneys had lesions similar to "leopard skin". The CT scan showed no enlarged lymph nodes. Renal biopsy showed: renal parenchyma largely occupied by infiltration of lymphoid elements, small and medium-sized, densely packed with compression of the tubular structures . Immunofluorescence for immunoglobulin (Ig) G, IgA, IgM, C3, C4, C1q, fibrinogen, kappa and lambda were negative. The bone marrow biopsy excluded lymphomatous infiltration. The histological diagnosis was "non-Hodgkin's B-cell lymphoma"; the clinical diagnosis was LRBP. The patient was treated by 6 cycles of R-CHOP-21 protocol (rituximab - endoxan, adriblastina , vincristine, prendnisone), the latter of which practiced in August 2011. The pt is currently in follow-up hematology and nephrology . The first TAC control , in October 2011, showed a complete regression of the lesions infiltrating . This finding was confirmed by two other CT scan performed in February and October 2012. The last blood tests of February 2013 showed : creatinine 1.1 mg / dl , Urea 40 mg/dl, proteinuria absent. Currently, the pt is asymptomatic and is being treated by low dose of ACE inhibitor. The bilateral PRL is considered a severe disease with one-year mortality of 75% . The successful outcome of the case described can be attributed to haematological therapy and to the early diagnosis.