Objective: Using mobile devices to identify the number of nursing actions and nursing practices practiced during the night shift at a comprehensive perinatal medical center. Methods: This study measured the type and number of nursing practices performed by a total of 56 members of the night shift staff in the maternity ward or Maternal-Fetal Intensive Care Unit of a comprehensive perinatal care center. Nursing practices consisted of 20 items partially modified from Table A of the Nursing Task Classification from the Japanese Nursing Association. Data were cross-analyzed by the role of staff members and their level of experience. Results: Nursing practices often performed by staff involved "safety checks," "hand over, notification, and reporting," and "nursing plans and records," all of which were required to ensure patient safety. Advanced beginner nurses tended to perform fewer nursing practices that required decision-making. Conclusion: Results confirmed that night shift staffing based on the level of experience is important in terms of midwifery management, at a facility dealing with a number of high-risk pregnant and postpartum women and newborns.