The study was based on 462 patients who underwent kidney transplantation from 1986 through 2004. Cyclosporine (CsA)-related thrombotic microangiopathy (TMA) was observed in 15 (3.3%) patients. The donor ages ranged from 9 to 51 years and cold ischemia times from 12 to 31 hours. Hemolytic-uremic syndrome (HUS) developed 2 weeks after transplantation in 14 patients and later in 1 subject. Histopathologic examination demonstrated glomerular-type TMA in 3 patients, a mixed type (glomerular and vascular) in 11 patients, and a nonspecific mesangial widening with tubulointerstitial lesions in 1 patient. Follow-up biopsies revealed resolution of TMA in 4 patients and chronic vascular TMA in 1 patient. Six patients with mixed-type TMA needed transient hemodialysis. No patient with the glomerular-type TMA needed dialysis (P = .103), and 14 of 15 had good resolution of graft function after CsA dose reduction or temporary discontinuation or continuation of optimal dose. Only 1 graft with mixed-type TMA was lost due to irreversible HUS. The mean glomerular filtration rate (GFR), predicted by the Nankivell equation, was 76 +/- 13 mL/min and 80 +/- 27 mL/min at 1 month after discharge for glomerular- and mixed-type TMA, respectively (P > .05). GFRs 1 year after HUS were 82 +/- 12 and 87 +/- 21 mL/min for the glomerular and the mixed types, respectively (P > .05). We concluded that the mixed-type TMA was associated with a more severe early clinical course than the glomerular-type TMA. The 1-year prognosis was good in the majority of patients, with no significant differences between those with the glomerular- and mixed-type TMA.