Renal involvement is common in leptospirosis. Bacterial invasion, inflammatory process, haemodynamic alterations and direct toxicity of bacterial products are thought to be responsible for the development of nephropathy. Pathologically, all renal structures are involved. Interstitial nephritis is the basic lesion, and is observed even in patients without clinical renal manifestations. Tubular necrosis is the important pathological counterpart of acute renal failure. The clinical spectrum of renal manifestations includes mild urinary sediment change, hypokalemia, tubular dysfunction, decreased response to fluid load and acute renal failure (ARF). ARF reflects the severity of leptospirosis, is catabolic and is commonly associated with cholestatic jaundice. Severe renal failure may be complicated by multiple organ involvement. Renal failure with hyperbilirubinemia represents a severe form of renal dysfunction with oligo-anuria and prolonged clinical course. Mild renal failure is usually anicteric and non-oliguric and without complication. Besides antibiotic treatment, early and frequent dialysis is life saving. ARF with major organ failure has unfavorable outcome. Plasmapheresis and continuous venovenous hemofiltration improve hemodynamics and are beneficial for the patients with acute renal failure and multiorgan involvement. Recovery of renal function is usually complete in most patients.