Background: Over the past several decades in Northern Thailand, there has been a contest of authoritative knowledge between the Hmong traditional birth system and the Thai biomedical maternity system. In this paper, we explore the contest in one Hmong village by describing the traditional and biomedical practices; families’ birth location choices; and elements of authoritative knowledge. Methods: We built on a village survey and conducted an ethnographic qualitative case study of 16 families who made different pregnancy care choices. Results: The contest is being won by the Thai biomedical system, as most families deliver at the hospital. These families choose hospital births when they evaluate problems or potential problems; they have more confidence in the superior Thai biomedical system with its technology and medicines than in the inadequate Hmong traditional system. But the contest is ongoing, as some families prefer to birth at home. These families choose home births when they want a supportive home environment; they embrace traditional Hmong birth knowledge and practices as superior and reject hospital birth practices as unnecessary, harmful, abusive, and inadequate. Despite their choice for any given pregnancy, the case study families feel the pull of the other choice: hospital birth families lament loss of the home environment and express their dislike of hospital practices; and home birth families feel the anxiety of potentially needing quick obstetrical assistance that is far away. Conclusion: While most families choose to participate in the Thai biomedical system, they also use Hmong pregnancy and postpartum practices, and some families choose home births. In this village, the contest for the supremacy of authoritative birth knowledge is ongoing.