This article dicusses the individual's choice to engage in informal care as an issue for economic evaluation. Traditional methods used in economic evaluation studies for valuing time spent on informal care are discussed and an alternative method is put forward that incorporates the quality of life of caregivers as an outcome measure to represent the effects on caregivers. The methodological issues concerning the valuation of informal caregivers' time are becoming more important as new drugs and other health care technologies are introduced for patients with diseases that are typically associated with informal care.