OBJECTIVE: To define the role of social theory and examine how research studies using qualitative methods can use social theory to generalize their results beyond the setting of the study or to other social groups. APPROACH: The assumptions underlying public health research using qualitative methods derive from a range of social theories that include conflict theory, structural functionalism, symbolic interactionism, the sociology of knowledge and feminism. Depending on the research problem, these and other social theories provide conceptual tools and models for constructing a suitable research framework, and for collecting and analysing data. In combination with the substantive health literature, the theoretical literature provides the conceptual bridge that links the conclusions of the study to other social groups and settings. CONCLUSION: While descriptive studies using qualitative research methods can generate important insights into social experience, the use of social theory in the construction and conduct of research enables researchers to extrapolate their findings to settings and groups broader than the ones in which the research was conducted.