It has been argued that traditional quasi-experimental approaches to evaluation do not adequately measure, or take account of, perceptual processes that could contribute to the effectiveness of organizational-level interventions. Using longitudinal data with added process measures at time 2 gathered from 11 intervention projects in Denmark, this paper used structural equation modelling (n = 462) to explore the impact of employees' direct appraisals of the intervention itself on intervention outcomes. Perceived influence on the content of interventions was directly linked to voluntary participation in these interventions. Participants' appraisals of the activities within an intervention were found to fully mediate the relationships between exposure to interventions and outcome measures (changes in working conditions, behavioural stress and job satisfaction). The results of the study indicate that employees' appraisal of the intervention itself can play an important role in determining the success or failure of a variety of organizational-level interventions. Copyright © 2007 John Wiley & Sons, Ltd.