The concepts of class, race, and ethnicity figure prominently in health services research in Britain. Occupational class has been employed for nearly a century to investigate social inequalities in health and access to care. More recently, researchers have identified differences in health status and utilization between ethnic groups. This article examines how these constructs are defined in Britain and identifies some key research associated with them. It also draws attention to the considerable problems in using class and ethnicity to stratify the population. The authors conclude that a new approach that directly measures individuals' material and social resources needs to be developed.