Background To determine whether diabetic nephropathy is a risk factor for silent cerebral infarction and whether anriplatelet drug, dilazep dihydrochloride decreases the occurrence of silent cerebral infarction in type 2 diabetes patients with microalbuminuria. Methods Two hundred four type 2 diabetes patients (124 men. 80 women; age, median 56 years, range 42-74 years) and 60 healthy age-matched subjects (no diabetes, normal renal function) were recruited for brain magnetic resonance imaging. The diabetes patients included 40 without nephropathy (group A), 42 with microalbuminuria (20-200 mug/min) (group 13), 44 with macroalbuminuria (>200 mug/min) and normal renal function (blood creatinine <132.7 mumol/L) (group C).. 33 with chronic renal failure but not undergoing haemodialysis (blood creatine >132.7 mumol/L; mean creatinine 335.9 mumol/L) (group D) and 45 undergoing haemodialysis (duration; median 4 years, range 3-6 years) (group E). Results Silent cerebral infarction was found in 20, 29, 34. 45, 53 and 8% of group A, B, C, D, E and control patients respectively. The incidence of silent cerebral infarction was increased with diabetic nephropathy. Thirty group B patients with no silent cerebral infarction were divided into two groups: (B1) 15 treated with dilazep dihydrochloride and (B2) 15 not treated with dilazep dihydrochloride. Treatment continued for 24 months. The incidence of silent cerebral infarction was significantly lower in the dilazep-treated patients (6.7%) than in the untreated patients (33.3%) (p<0.01). Conclusions These data suggest that diabetic renal dysfunction increases the risk of silent cerebral infarction and that dilazep dihydrochloride prevents its onset in early type 2 diabetic nephropathy patients. Copyright (C) 2004 John Wiley Sons, Ltd.