Health and illness are not objective states but socially constructed categories. We focus here on infertility, a phenomenon that has shifted from being seen as a private problem of couples to being seen as a medical condition. Studying infertility provides an ideal vantage point from which to study such features of health care as inter-societal and cross-cultural disparities in health care, the relationship between identity and health, gender roles, and social and cultural variations in the process of medicalization. Infertility is stratified, both globally and within Western societies. Access to care is extremely limited for many women in developing societies and also for marginalized women in some highly industrialized societies. We also discuss the ways in which responses to infertility are influenced by the process of self-definition. The experience of infertility is profoundly shaped by varying degrees of pronatalism and patriarchy. In advanced industrial societies, where voluntary childfree status is acknowledged, many women experience infertility as a ‘secret stigma’; in other cultures, where motherhood is normative for all women, infertility may be impossible to hide. In the West, acceptance of the medical model is virtually hegemonic, but in other societies medical interpretations of infertility coexist with traditional interpretations.