Aims Identifying the causes of midwifery errors and providing appropriate solutions to reduce these errors play an important role in providing health care for women and society. This study aimed to identify occupational factors leading to obstetric errors from midwives’ viewpoints working in obstetrics and health centers. Instrument & Methods This descriptive study was conducted on 252 midwives working in the delivery block and health centers of three Shahid Beheshti, Tehran, and Iran University of Medical Sciences in 2014. A researcher-made questionnaire was used to conduct the research. Data were analyzed by SPSS 16 software using descriptive statistics and Mann-Whitney. Legal errors were also prioritized based on the experiences of midwives or one of their colleagues. Findings The results of the Mann-Whitney test showed that except for five variables of midwifery professional responsibility insurance, midwifery hard work, patient referral problems, authorities’ characteristics, and material satisfaction with the job, the rest of the variables had the same role in the incidence of midwifery errors from the perspective of the two groups (P>0. 05). Also, the first to the fourth priority of the errors occurred was based on the experiences of midwives working in the delivery block, carelessness, indiscretion, lack of skill and non-compliance with governmental laws and from the perspective of midwives working in health centers, indiscretion, carelessness, lack of skills and lack of compliance with government laws. Conclusion Identifying the causes of midwifery errors, especially from the perspective of employed midwives, is of particular importance in controlling and reducing the errors of this profession.