The genogram is a tool that can be used by health professionals to provide a comprehensive, holistic picture of the client and his environment. The realization of the genogram in medicine allows recognizing, clarifying and expanding information on risks and health problems in the individual and the family, both of a biological, psychological and social nature. This has beneficial implications for the doctor-patient relationship, for diagnosis, treatment, long-term follow-up of the patient, prognosis, screening, preventive care, focus on care of those most at risk, and to implement proactive assessment and educational programs. The genogram has also applications on preventive medicine and public health, to identify pathways of transmission in epidemiological studies, and it is a biomedical, health economics and public health research tool, as well as a qualitative research method. The genogram is a tool that connects individual care with community care. The exercise of community medicine in general medicine is "contextual medicine", which means knowing, sharing, intervening on the connections in the patient's relational matrix. Physicians, patients, community and Health Public system benefit from the thorough histories collected by genograms.