Background: Reorganization of the Army and critical assessment of Army Graduate Medical Education programs prompted the Occupational and Environmental Medicine (OEM) Consultant to the Army Surgeon General to initiate a review of current Army OEM residency training. Available information indicated the Army OEM residency at Aberdeen Proving Ground, MD, was the first and longest operating Army OEM residency. Describing this residency was identified as the first step in the review, with the objectives of determining why the residency was started and sustained and its relevance to the needs of the Army. Methods: Records possibly related to the residency were reviewed, starting with 1954 since certification of physicians as Occupation Medicine specialists began in 1955. Interviews were conducted with selected physicians who had strong affiliations with the Army residency and the practice of Army OEM. Findings: The Army OEM residency began in 1960 and closed in 1996 with the transfer of Army OEM residency training to the Uniformed Services University of the Health Sciences, Bethesda, MD. Over 36 years, 47 uniformed residency graduates were identified; 44 were from the Army. Forty graduated between 1982 and 1996. The OEM residency was part of a dynamic cycle. Uniformed OEM leaders identified the knowledge and skills required of military OEM physicians and where these people should be stationed in the global Army. Rotations at military sites to acquire the needed knowledge and skills were integrated into the residency. Residency graduates were assigned to positions where they were needed. Having uniformed residents and preceptors facilitated the development of trust with military leaders and access to areas where OEM physician skills and knowledge could have a positive impact. Early reports indicated the residency was important in recruiting and retaining OEM physicians, with emphasis placed on supporting the Army industrial base. The late 1970s into the 1990s was a more dynamic period. There was heightened interest in environmental protection and restoration of military installations, and in the threats posed by nuclear, biological and chemical weapons. Additionally, President Reagan initiated a military buildup that brought new health risks to soldiers who would use and maintain modern equipment. Army OEM physicians were required to possess competencies in many areas, to include depots in the Army industrial base, occupational health for the soldier for exposures like carbon monoxide in armored vehicles, military unique exposures like those from chemical threat agents, and environmental medicine to assess health risks on contaminated U.S. military sites and from exposures of deployed forces. These offered interesting OEM training opportunities that challenged residents in the program and helped recruit new residents. Discussion: The strength of the first Army OEM residency was that it was part of a dynamic cycle that consisted of identifying and defining Army OEM needs, training physicians to meet those needs and assigning residency graduates to positions where they would have a positive impact. This paradigm can be used as the basis for contemporary assessments of the Army’s need for uniformed OEM physicians and a uniformed OEM residency program.