The present retrospective study provides an in-depth analysis of the maternal sepsis-related deaths reported in Japan, and aims to guide future care regarding maternal sepsis. This is a nationwide, retrospective, descriptive cohort study. Data were retrospectively analyzed on all maternal death cases related to sepsis reported in Japan from 2010 through 2016. A total of 7,347,727 births and 317 maternal deaths were reported during the study period. The cause of maternal death was sepsis in 24 women (7.5%). Causative bacteria were Streptococcus pyogenes (54.2%), Chlamydia psittaci (8.3%), Mycobacterium tuberculosis (8.3%), Escherichia coli (4.2%), Neisseria meningitidis (4.2%), Epstein-Barr virus (4.2%), and unknown (16.6%). In maternal death due to S. pyogenes (13 women), onset periods ware antepartum in 10 women (76.9%) and postpartum in 3 (23.1%); death within 24 h after hospital admission occurred in 7 women (53.8%); and the median time from hospital admission to death was 12 h (6e744 h). The most common causative bacteria in to maternal sepsis-related death were GAS. When encountering severe sepsis during the peripartum period, we recommend considering severe GAS infection and early intervention.