Objectives: This article reports the results of the application of conjoint analysis (CA) to derive a monetary value of informal care. Compared with normally recommended valuation methods such as the opportunity cost method and proxy good method, a valuation elicited through a CA might be more sensitive to the heterogeneity and dynamics of informal care. Methods: We developed a questionnaire and conducted a survey in which informal caregivers were asked to rate four different hypothetical informal caregiving situations (reflecting different combinations of care hours, care tasks, and monetary compensation). They were also asked to rate their current informal care situation compared with the four hypothetical situations. Data were obtained from postal questionnaires. These questionnaires were sent through regional support centres for informal caregivers of care recipients with various health problems. A total of 865 informal caregivers from this heterogeneous population returned a completed survey. Results: Informal caregivers require an increase of 81% in their hourly compensation for providing 21 instead of 7 hours informal care per week. This implies a compensation of €12.36 per hour at a mean hypothetical compensation in the presented scenarios. We also found that an informal caregiver's current caregiving situation and other background characteristics were associated with the scenario ratings. Conclusions: We conclude that a CA is a promising alternative for existing methods to determine a monetary value of informal care and encourage more experiments in this area. © 2008, International Society for Pharmacoeconomics and Outcomes Research (ISPOR).