From 2002 to 2007 the Italian Society of Industrial Medicine and Industrial Hygiene (S.I.M.L.I.I.) produced, in the context of the specific Education and Accreditation Programme for occupational physicians, more than 20 guide lines and consensus document on the most important and controversial themes for our Discipline. These instruments have aimed not only to improve the effectiveness of preventive actions but also to constantly adopt rigorous methodologies based where possible on evidence based medicine procedures. The Italian Occupational physicians agree with guidelines of our Scientific Society, but it appears now to be necessary to critically evaluate our experience, at the light of the new Framework Act for the occupational safety and health "Decreto legislativo 81/08" signed by the President of the Italian Republic on April 9, 2008, which firstly included in a legislative act terms such as technical normative, good practices, guide lines. Another important, mandatory reference, for a Medical Discipline as Occupational Medcine remains, in this debate is, in our Country, the National Program for Guide Lines edited By Italian National Health Institute since 2002 and part of current National System of Guide Lines concerning preparation, dissemination, updating, implementation of guide lines in Medicine. In this paper the main aspects related to different kind of instruments such as guide lines, consensus conference reports, technology assessment, good practices, technical normative, focusing in particular the argument identification, methodology, relationship between different instruments and their production and diffusion, economical and ethical issues and possible conflict of interest.