Purpose: This article assesses the state of research on assisted living (AL) from 1989 to May 2004. Design and Methods: We undertook keyword searches for AL research and amplified these with searches of Web sites, conference proceedings, and follow-up inquiries. We annotated and coded the resultant items according to categories reflecting the research methods used and the topics studied. We did additional comparisons for 38 studies with quantitative data that permitted summarizing resident characteristics, settings, and entry and move-out patterns. Results: The 411 identified items ranged across a large number of topics. Qualitative studies outnumbered quantitative ones, and longitudinal studies were rare. We found little standardization in the way variables were measured, making cross-study comparisons difficult. As AL research has become more common, some items are directed at studying ways to proceed within AL as opposed to globally commenting on the worth of AL as a service sector. Implications: The research base for AL has grown rapidly but is still underdeveloped. We recommend using more consistent sets of standardized measures in AL studies and reporting analyses based on them. We also recommend fuller reporting of details on sampling, time frames, and measures in AL research.