Adult Day Service (ADS) centers offer a variety of services to meet the needs of older adults and their caregivers. During the last decade, ADS has received increased attention due to shifts in policy toward home and community-based services for an aging population. This article reviews the effectiveness of ADS from 2000 to the present, with particular attention given to caregiver and participant outcomes, health care utilization, and future directions in ADS research. Multiple databases were searched to identify relevant research and 61 articles were selected for review based on inclusion criteria. The results of this review emphasize the need to implement and test more specific interventions targeting the needs of the ADS population.