The aim of our work is to describe essential aspects of Medical Informatics, Bioinformatics and Biomedical Informatics, that are used in biomedical research and clinical practice. These disciplines have emerged from the need to find new scientific and technical approaches to manage, store, analyze and report data generated in clinical practice and molecular biology and other medical specialties. It can be also useful to integrate research information generated in different areas of health care. Moreover, these disciplines are interdisciplinary and integrative, two key features not shared by other areas of medical knowledge. Finally, when Bioinformatics and Biomedical Informatics approach to medical investigation and practice are applied, a new discipline, called Clinical Bioinformatics, emerges. The latter requires a specific training program to create a new professional profile. We have not been able to find a specific training program in Clinical Bioinformatics in Spain.