We report on a study in which 487 Danish general practitioners participated with the purpose of including all newly-diagnosed diabetic patients aged 40 years or more from a well-defined catchment population during a well-defined time period. A total of 1267 diabetic patients with a median age of 65.3 years were included. Renal involvement was assessed from the albumin/creatinine ratio in a morning urine sample. Albumin/creatinine ratio was < 2/2- < 20/ > or = 20 mg/mmol in 59.8/33.6/6.6% of male and 66.6/28.8/4.6% of female patients. The level of albumin/creatinine ratio increased with age and the observed overall male predominance was almost confined to diabetic patients with an albumin/creatinine ratio of 5 mg/mmol or greater. By taking into account the confounding effect of age and sex, a positive association between smoking and albumin/creatinine ratio was disclosed. Moreover, high systolic blood pressure, hypertriglyceridaemia, hypercholesterolaemia (males only) and high HbA1c, but not body mass index or diastolic blood pressure were identified as correlates of elevated albumin/creatinine ratio. Glucosuria was positively correlated with albumin/creatinine ratio even when the influence of HbA1c, sex and age was taken into account. A positive correlation between serum creatinine and albumin/creatinine ratio was seen in males, but not in females. In addition, renal involvement was associated with the presence of peripheral angiopathy and diabetic retinopathy and with high resting heart rate. The cross-sectional data presented highlight the importance of reducing the overall burden of modifiable risk factors in newly-diagnosed Type 2 diabetic patients.