Treatment with a self-adhesive hydroactive polyurethane dressing (Cutinova thin, Beiersdorf AG, Hamburg, Germany) applied over a period of eight weeks has been shown to have a beneficial effect on hypertrophic scars. However, the use of such dressings during the daytime on visible parts of the body is often problematic and might lead to reduced compliance. In the present study the effect of 12-hour (overnight) treatment was compared with the results of a 24-hour treatment regimen with the same dressing. The dressings were applied over an eight-week period. Evaluation of the hypertrophic scars was by clinical assessment and measurement of colour difference to normal skin, elevation and elasticity. In addition, the patients assessed the treatment effects (questionnaire) and photographs were taken. Under both regimens an improvement in the scar colour (redness) and visual assessment scores took place. The patients also gave a positive assessment of the effects of the treatment. After eight weeks there were no relevant differences between the scars treated with the self-adhesive dressings for 12 hours (overnight) and those treated for 24 hours per day.