Purpose. Examine the effects of three iterative tailored feedback letters addressing smoking,physical activity; and fruit, vegetable, and fat intake, and test the additional effects of providing feedback on action plans. Design. A tailored, print-based intervention was developed and tested in a randomized control trial with a posttest after 9 months. Setting. A total of 2827 respondents agreed to participate. They were recruited from a random sample of 35, 000 addresses obtained through. the Dutch national telephone company. Subjects. The mean age was 49 years, and 55 % were female. Intervention. The experimental group received three printed tailored letters, and the control group received three printed generic letters. Respondents from the experimental group randomly received either a third letter with tailored information or tailored information and action-planning feedback. Measures. The questionnaire assessed physical activity; smoking; consumption of fruit, vegetables and fat; motivational determinants; action plans; and demographics. Results. Tailored information resulted in more improvement over time than generic information for the intake of fruit, vegetables, and fat and for physical activity. No differences between the conditions were found for smoking because of high cessation rates in all conditions. Action-planning feedback did not increase the effects. Conclusions. Tailored lifestyle information can be effective for adults in changing nutrition behavior and physical activity.