Background: Maternal mortality is an indication of the health status of women in the society. Aims: To investigate the maternal mortality ratio, causes of maternal mortality, and related risk factors among Iranian women. Methods: Using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) checklist and the Peer Review of Electronic Search Strategies (PRESS) guideline, we systematically searched electronic databases, and the grey literature, for publications in Farsi and English from 1970 to January 2022 for studies that reported the number of maternal deaths and/or maternal mortality ratio and their related factors. Data analysis was conducted using Stata 16 and 2-sided P ≤ 0.05 was considered statistically significant, if not otherwise specified. Results: A subgroup meta-analysis of studies conducted since 2000 estimated the maternal mortality ratio as 45.03 per 100 000 births during 2000–2004, 36.05 during 2005–2009, and 23.71 after 2010. The most frequent risk factors for maternal mortality were caesarean section, poor antenatal and delivery care, unskilled birth attendance, age, low maternal education level, lower human development index, and residence in rural or remote areas. Conclusion: There has been a significant decrease in maternal mortality in the Islamic Republic of Iran during the last few decades. Mothers in the country need to be monitored more carefully by trained healthcare workers during the pregnancy, delivery and postpartum periods so they can effectively handle postpartum complications, such as haemorrhage and infection, thereby further reducing maternal mortality.