Background: Physicians have not learned their role as patients. Medical associations focused mainly on mental health programs for doctors in different countries. Nevertheless, the anomalous behaviours of ill doctors exist independently of their health problem. We described the development and validation of a questionnaire to describe Behaviours and Attitudes of Doctors towards their Own Illness (BADOI).Methods: Development of the questionnaire and appearance and content validation (ACV) by experts’ debriefings; construct validation by exploratory (EFA) and confirmatory factor analysis (CFA); reliability by Cronbach's alpha index (CAI) and feasibility by completion time (CT), accessibility to questionnaire platform and % of not answer items.Results: A Questionnaire with 56 items was developed with 3 sections: 1) socio-demographic, professional and work-related data. 2) Activities for self-care and work impact (sick leaves and presenteeism) and physicians’ healthcare pathways (Self-management and use of healthcare services). 3) Doctors of ill doctors and the role of medical associations. The validation sample size was of 4308 physicians’ answers. The factorial model presented 5 factors explaining 78.08% variance, a high value. Factor 1 explained 26.75% of the model describing the relationship between illness and work; Factor 2 explained 16.68%, with items regarding the negative impact of mental issues, toxic habits and the use of healthcare services; Factor 3 explained 15.06%, with items considering presenteeism and sick leaves; Factor 4 explained 9.95% regarding the handling of an ill colleague and medical associations. Finally, Factor 5 explained 9.64%, with items describing healthcare given to ill physicians and the revalidation of medical profession. Discussion: The factors grouped together items relating to self-care, impact on work and physicians’ healthcare pathways (F1-F2-F3) and the role of doctors of ill doctors and of the professional associations (F4-F5), being consistent with the 2 main perspectives: personal experience and caring for ill colleagues.Conclusion: A reliable Multidimensional Questionnaire on the process of physicians becoming ill has been validated in a large sample of registered doctors. It will help to identify and quantify physicians’ healthcare pathways allowing healthcare managers to set evidence-based interventions and formulate policies and ethical recommendations regarding the management of sick doctors.