The Ethical Risk Assessment (ERA) allows highlighting the critical points or hazards that could occur during the execution of the OPU procedure compromising its accomplishment, and to assess the animal welfare risks. The application of ethical principles in the analysis of the risk, together with a risk ethics approach, provides a deeper analysis of the hazards and allows ethical consideration to be part of risk-related decisions. Therefore, ERA provides a base for the ethical decision-making and allows the assessment of the ethical acceptability of the procedure. For this purpose, the OPU procedure has been divided into different phases (from phase A to phase E - figure 1). Each phase has been analyzed using a detailed checklist built to identify the safety and ethical hazards and the animal welfare issues. Each item of the ERA checklist is conceptually linked and mutually integrated into an Ethical Evaluation sheet - EES (the alpha-numerical code of the first column). EES comprises the relevant ethical aspects that need to be detailed in ERA. In case of potential harms or risks, identified by the failure to reach a minimum threshold on the ERA score, corrective actions will be planned to mitigate the risks for the success of the procedure and for the animal health and welfare. The measures for the risk mitigation consist of implementing activities for reaching an acceptable fulfilment of the requirements defined in ERA or, to alleviate the adverse effects that might arise. The “as low as reasonably practicable” principle will be applied. This principle expresses that the risk should be reduced to a level that is low as reasonably practicable unless it can be demonstrated that there is a great disproportion between costs and benefits.