This article examines knowledge and practice surrounding birth in Morocco, using women's narratives of their recent birth experiences, observations of medical encounters, and statements about prescribed behaviors during pregnancy and birth, as well as the vocabulary used to refer to physiological processes, disease conditions, and social relationships. The analysis shows that the three major themes that define the traditional Moroccan ethnophysiology of birth--conceptions of hot and cold, the symbolism of blood, and the metaphors of openness and obstruction--are not inconsistent with the precepts of biomedicine and public health and do not in themselves constitute obstacles either to safe home births or the use of formal health services. Women integrate biomedical and local knowledge and practices and simultaneously seek care from "traditional" and "modern" practitioners, creatively combining elements in accordance with their situations and the means at their disposal. Birth narratives show the eclecticism and flexibility that characterize women's attitudes and behaviors regarding pregnancy and birth. Women's decisions are shaped by two overriding considerations: incertitude about what can happen during the last phase of a pregnancy and ambivalence toward the available alternatives for care, both of which reflect a realistic assessment of their situations. By showing how women make decisions in response to these considerations, this article seeks to clarify some of the links between beliefs and practices and to contribute to ongoing discussions regarding the relevance of local knowledge for patterns of health care.