Aims To examine prospectively the relationship between vascular risk factors and stroke in Type 1 diabetes.Methods A community-based sample of 126 adult Type 1 patients was recruited between 1993 and 1996 and followed annually for a mean +/- sd of 7.2 +/- 1.6 years. Cerebrovascular events before and after recruitment were identified from history and examination findings, hospital morbidity data and death notifications.Results Six patients suffered a first stroke during follow-up, of which five were ischaemic and one a subarachnoid haemorrhage on cranial computed tomography. Patients were subdivided into those with no history of stroke/transient ischaemic attack (TIA) at baseline and no subsequent ischaemic stroke (Group 1, n = 114), those with a history of stroke/TIA at baseline (Group 2, n = 7), and those with no history of stroke/TIA at baseline but who suffered a first ischaemic stroke during follow-up (Group 3, n = 5). Group 1 patients were the youngest, had the shortest diabetes duration and were the least likely to be taking antihypertensive medication or aspirin. Amongst a range of potential baseline predictors of first stroke including glycated haemoglobin, only serum HDL-cholesterol differentiated Group 3 patients (0.69 +/- 0.17 mmol/l) from those in the other groups (1.26 +/- 0.42 and 1.28 +/- 0.45 mmol/l for Groups 1 and 2 respectively, P < 0.05).Conclusions The present association between low serum HDL-cholesterol and ischaemic stroke patients suggests that aggressive management of dyslipidaemia may protect against cerebrovascular disease in Type 1 diabetes.