This paper suggests that, for a variety of reasons, the sociology of social stratification--and, as a consequence, mainstream sociology more generally--has neglected the topic of disability. Using material drawn from a range of sources, it is argued that disability is related in definite ways to social class. Further, it is also argued that disability must be considered as a factor contributing to the production and reproduction of stratification in its own right, independently of class relations. These arguments are further advanced in the course of a more detailed consideration of research evidence concerned with mental handicap. The paper ends with a consideration of the role of non-class factors--specifically social status and citizenship--in the stratification systems of modern industrial societies.