According to the UN-CRPD, cities must develop action plans about universal accessibility (UA). Operationalization of these plans is complex, and little is known about what municipal employees know about UA. Aim: The aim is to document implementation determinants of UA within a municipal organization in Quebec, Canada. Methods: An observational cross-sectional study was performed. Employees answered a survey based on the TDF and the DIBQ. Facilitators, barriers, and factors influencing the determinants were identified. Results: A total of 43% of the employees completed the survey. The implementation of UA measures is more facilitated by their beliefs about the impact on citizens, while the external context hinders the proper implementation. It is also influenced by six factors: (1) professional role, (2) capacity, (3) resources, (4) willingness, (5) characteristics, and (6) feedback. Discussion: Results suggest that understanding the consequences, sufficient resources, abilities, and willingness can influence implementation of UA. Conclusion: These findings have informed the objectives of the next action plan of the municipal organization and could guide the development of solutions.