Objective: To develop a realistic simulation model for laparotomy-assisted fetoscopic spina bifida aperta (SBa) surgery, to be used for training purposes and preoperative planning. Methods:The predefined general requirement was a realistic model of an exteriorized uterus, allowing all neurosurgical steps of the intervention. The uterus was modelled using ultrasound and MRI images of a 25 weeks' gravid uterus, consisting of flexible polyurethane foam coated with pigmented silicone. The fetal model, contained an opening on the dorsal side for a customizable spinal insert with all the aspects of a SBa, including a cele, placode, and myofascial and skin layer. The model was assessed in a series of validation experiments.Results: Production costs are low, uterus and fetus are reusable. Placental localization and the level and size of the spinal defect are adjustable, enabling casespecific adaptations. All aspects of the simulator were scored close to realistic or higher for both appearance and functional capacities. Conclusions:This innovative model provides an excellent training opportunity for centers that are starting a fetoscopic SBa repair program. It is the first simulation model with adjustable spinal defect and placental localisation. Further objective validation is required, but the potential for using this model in preoperative planning is promising. Key points What is already known about this topic?� Fetal surgery is a well-known option for the treatment of myelomeningocele (MMC), yet the downside of the open procedure is its invasiveness. Fetoscopic surgery may be an option to overcome at least part of these complications but comes with a long learning curve.� Simulation models may prove themselves effective in shortening these learning curves; however, for MMC, the current models are either expensive, animal based, or low fidelity.This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.