Abstract Study question Is systematic patient safety management training effective in improving awareness in safety confirmation and preventing errors in Embryo mix-up for embryologists? Summary answer From survey for 116 embryologists, they responded that they followed safety management instructions and regulations, and that they improved their safety work capability and awareness What is known already The cases of embryo mix-up known through the media include errors of sperm change during IUI, fertilization, Freeze-thawing, PGT, and Embryo transfer process, but there will be more due to statistical difficulties. Errors mostly occur because clinics do not have the right protocol. Currently, there aren’t any regulations or policies to track eggs, sperm, embryos or frozen embryos during ART. For this reason, infertile couples have to choose clinics with high pregnancy rates and safe clinics on their own to perform assisted reproductive techniques. Study design, size, duration This study was conducted through a survey of 116 embryologists who worked at five clinics of CHA fertility centers. The patient safety management system was created from the CHA fertility Center itself. From August 2021 to December 2022, safety confirmation training was conducted for 16 months. All embryologists were anonymously surveyed twice with 32 questions. The first survey was conducted in April 2022, and the second survey was in December 2022. Participants/materials, setting, methods The survey was conducted in 32 items with 10 categories. Interviewees’ made response for each item in five steps. Each item asked 1) Learning in the standard safety manual 2) Changes in safety awareness before and after training, 3) Compliance to the seven safety instruction (double checks) for each work part, 4) Level of difficulty in education, 5) Effects of education and 6) Suggestions for safety confirmation. Main results and the role of chance In the first survey, 61 out of 112 responded (54.5%) 60 out of 116 (51.7%) in the second. The answers were scored using a 5-point Likert scale (1 = strong disagree, 5 = Strong agree). 1. The mean score for work satisfaction was 3.1 ± 0.8 out of 5 in the first survey and 3.1 ± 0.7 out of 5 in the second. Work satisfaction remained unchanged. 2. The perception of patient safety confirmation was 3.7/5 before training and 4.0/5 after training (p < 0.03) in the second which improved the perception of safety confirmation. 3. The safety confirmation ability through training was improved to 4.1/5(p < 0.01) after training compared to 3.8/5 in both the first and second surveys. 4. The necessity and importance of safety training were considered important in the first survey as it scored 3.6/5 and 4.5/5 (p < 0.001) in the second survey. 5. In the course of work, they responded that their safety management skills were improved (1st: 3.4/5, 2nd: 4.5/5(p < 0.05)) by the effects of training. As for CHA IVF lab, the embryologists were well aware of the guidelines (scoring 4.5/5 in the first and second survey) to know seven safety instructions (which are double check, outloud, RI witness, monitoring, document, information) should be followed well. Limitations, reasons for caution Embryo mix-up during ART procedures can be a major mistake to be avoided. The confirmed documentations can make errors any time. Establishing the safety protocol of the same process as ART procedure, the system, and education are important, but the most important is the safety management capability of the manager. Wider implications of the findings The safety management manual, the 7 CHA IVF laboratory patient safety instructions, online lecture training, field training, and inspection have raised awareness of the safety errors and the importance of double checking. Errors in safety can be prevented through systematic system development and repeated safety training. Trial registration number non-clinical trials