The aim of the present study was to determine the long-term effects of a burnout-intervention program among Dutch dentists using a longitudinal design. Using the Maslach Burnout Inventory (Dutch version: MBI-NL), at the initial measurement in 1997 a 'burnout risk group' (n = 171) was identified. This group received feedback on their scores and was invited to participate in an intervention program. Of the total group. 19 dentists participated in an intervention program. After the end of the intervention program, 92 dentists (the 19 participants and a control group) responded to a post-intervention survey in 1998. These dentists were approached once more 1 yr later, and this time 78 dentists (84.8%) returned a questionnaire. While demonstrating an improvement on all subscales of the MBI-NL at the first post-test, results show that the program participants showed a relapse at the second post-test. Controls who took action on their own initiative, on the other hand, reported a beneficial effect in the long run. Finally, controls that did not take any preventive action showed little or no progress. Possible causes for these findings are discussed, including the influence of coping style. perceived control, confounding factors, demand characteristics, and the necessity of post-intervention follow-up.