This study explores the phenomenon of the informal medical consultation, a communication event in which an individual asks for medical information, advice, or care from an off-duty health professional with whom the individual has no formal patient-provider relationship. Using surveys and interviews, the study describes these consultations from the perspective of the health care professional and the informal patient. The study explores foundational theories that offer explanations for the phenomenon. The theories considered include social support, decision-making, social exchange, perceived partner responsiveness to needs, and uncertainty management. This study suggests health care providers perceive informal medical consultations to be more problematic than do the informal patients who consult them. The problematic nature of informal consultations increases as the type of request moves from purely informational to a request for treatment. Informal patients do not perceive this distinction. The informal patient’s motivation to pursue an informal consultation instead of a formal consult is affected by the relationship with, trust in, and access to the informal consultant. The willingness of the informal consultant to engage in an informal consultation is affected by the relationship with the informal patient, the type of request made, and perception of risk/benefit for both the provider and the patient. The study supports the idea that informal medical consultations are potentially problematic within the current medico-legal-ethical environment. Alternately, these consultations may be viewed as offering positive contributions to the health and well-being of informal patients. The study suggests translational research is needed to guide health professionals in considering requests for informal medical consultations.