The evaluation of the competence of personnel working with laboratory animals is currently a challenge. Directive 2010/63/EU establishes that staff must have demonstrated competence before they perform unsupervised work with living animals. Nevertheless, there is a lack of research into education and training in laboratory animal science, and the establishment of assessment strategies to confirm researchers’ competence remains largely unaddressed. In this study, we analysed the implementation of a practical assessment strategy over three consecutive years (2018–2021) using the Objective Structured Laboratory Animal Science Exam (OSLASE) developed previously by us to assess professional competence. The interrater reliability (IRR) was determined based on the assessors’ rating of candidates’ performance at different OSLASE stations using weighted kappa (Kw) and percentage of agreement. Focus group interviews were conducted to access trainees’ acceptability regarding the OSLASE. There was a moderate-to-good Kw for the majority of the scales’ items (0.79 ± 0.20 ≤ Kw ≥ 0.45 ± 0.13). The percentages of agreement were also acceptable (≥75%) for all scale items but one. Trainees reported that the OSLASE had a positive impact on their engagement during practical training, and that it clarified the standards established for their performance and the skills that required improvement. These preliminary results illustrate how assessment strategies, such as the OSLASE, can be implemented in a manner that is useful for both assessors and trainees. Examen structuré objectif de science animale de laboratoire (OSASSE) pour assurer la compétence professionnelle des chercheurs en SAL