Objective: The Fenofibrate Intervention and Event Lowering in Diabetes (FIELD) Study is examining the effects of long-term fibrate therapy on coronary heart disease (CHD) event rates in patients with diabetes mellitus. This article describes the trial's run-in phase and patients' baseline characteristics. Research design and methods: FIELD is a double-blind, placebo-controlled trial in 63 centres in 3 countries evaluating the effects of fenofibrate versus placebo on CHD morbidity and mortality in 9795 patients with type 2 diabetes mellitus. Patients were to have no indication for lipid-lowering therapy on randomization, but could start these or other drugs at any time after randomization. Follow-up in the study was to be for a median duration of not less than 5 years and until 500 major coronary events (fatal coronary heart disease plus nonfatal myocardial infarction) had occurred. Results: About 2100 patients (22%) had some manifestation of cardiovascular disease (CVD) at baseline and thus high risk status. Less than 25% of patients without CVD had a (UKPDS determined) calculated 5-year CHD risk of <5%, but nearly all had a 5-year stroke risk of <10%. Despite this, half of the cohort were obese (BMI >30), most were men, two-thirds were aged over 60 years, and substantial proportions had NCEP ATP III features of the metabolic syndrome independent of their diabetes, including low HDL (60%), high blood pressure measurement (41%), high waist measurement (65%), and raised triglycerides (52%). After a 6-week run-in period before randomisation with all participants receiving 200 mg comicronized fenofibrate, there were declines in total and LDL cholesterol (10%) and triglycerides (26%) and an increase in HDL cholesterol (6.5%). Conclusion: The study will show the effect of PPAR-alpha agonist action on CHD and other vascular outcomes in patients with type 2 diabetes including substantial numbers with low to moderate CVD risk but with the various components of the metabolic syndrome. The main results of the study will be reported in late 2005.