The purpose of this study is to examine the Swedish practice of co-sleeping and relate it to the cultural discourse on the gendered family and health. The Swedish study, part of the International Study of Parents, Children and Schools, focuses on some Western parents' ideas about health, child development, child-rearing goals and parental practices. It also addressed specific questions regarding parents' theories about the nature, gender and frequency of co-sleeping in Swedish families. Quantitative and qualitative data were collected with five cohorts of parents and their 60 children who ranged in age from 6 months to 8 years. The sample was balanced for sex and birth order. Parents completed batteries of standardized questionnaires and they were interviewed about their beliefs and practices related to child rearing and child development. A questionnaire about co-sleeping was sent post hoc to the families. The results showed that Swedish children often co-sleep with both their parents until school age, when more boys than girls cease the practice. This is an important finding, because much of the literature suggests that this practice exists primarily for infants in non-Western cultures who co-sleep with their mothers. Co-sleeping in Sweden is perceived as a normal family activity, which differed from the other societies studied. Thus, the study of practice has important methodological implications. When a family practice is studied, carefully documented and understood in its many dimensions, it provides a window into the culture in which the practice is embedded and may explain how gender relates to the practice. For health-care professionals who encounter families from diverse cultural backgrounds, this methodological approach illustrates how parenting practices relate to health-care issues.