Aims: To examine the impact on health-related lifestyle of conducting a targeted stepwise diabetes screening programme. Methods: A total of 4731 people aged 40-69 years were offered stepwise diabetes screening in part of the Danish arm of the ADDITION-study in the county of Aarhus, Denmark. The screening comprised two main steps: identification of high-risk individuals by a mailed risk score questionnaire, and subsequent testing of high-risk individuals by their general practitioner. Questionnaires on physical exercise [International Physical Activity Questionnaire (IPAQ), short form], smoking habits and alcohol consumption were mailed to the target population 1 month prior to the offer of screening, and at 12 months' follow-up. At follow-up, additional questions regarding perceived changes in dietary habits, smoking, alcohol consumption and exercise were included. Three pairs of comparison groups were analysed. Results: One year after screening, smokers who underwent further testing reduced smoking by one daily cigarette more than people at low risk of diabetes. The rate of smokers was not reduced, and the result was not confirmed by data regarding perceived change. Alcohol intake and exercise were unchanged. Data on perceived changes showed that more people undertook increased exercise in the group at low risk than in the further examined group, but this was not seen when comparing high-risk attenders with non-attenders. Dietary habits were unchanged, except that slightly more people in the group with an abnormal test result reported increase of fruit and vegetable intake and reduction of fat intake compared with the group with a normal test result. Conclusion: Only minor and inconsistent impacts on lifestyle was observed 1 year after screening.