The authors, Professors of different Universities, of this book are introduced in the Epidemiology principles and concepts and to fcilitate comprehension and retention new material with relevant to evidence based medicine and the affectivity relationship in the care of the patients. The aims provide specific topic areas: Measuring disease frequency, describing pattern of disease occurrence, the utility of diagnosis test, the clinical areas of application, infectious and chronic diseases, ad prevention, vaccination shedules identifying the causes of diseases, effectiveness of treatment, decision making about treatment strategies. The measure to impact of disease in population, according the social and demography patterns, necessary for determining health Management and Medical service needs it is written concisely and can be used as a stand study guide.