Clinical guidelines are statements that have been systematically developed and which aim to assist clinicians in making decisions about treatment for specific conditions. They are linked to evidence and are meant to facilitate good medical practice. A key issue that follows is how lawyers and the courts might use such guidelinesin medical litigation. The multiplicity of opinions and scientific professions requiring expertise might influence the expert submitting an opinion to base his opinion on scientific theses which have not been recognized scientifically, are not based on facts and are not supported by professional literature. Medical evidence has to be methodically based and reliable. In recent years the medical community has developed a new field called "Evidence Based Medicine", meaning, use of medical information based on the best information in the medical literature relevant to the condition being treated. Evidence Based Medicine distinguishes between recognized scientific theories and what is called "Junk Science". Clinical Guidelines are of value in systematizing medical procedures, mainly those which may have legal implications. In other procedures Guidelines may serve the Court as a source of sound information, provided they are the product of a recognized professional body, and proven to bear no relation to a body which may have interests in the delivery of healthcare. Clinical guidelines are set as normative standards and used as a tool to indicate the standard of care at the time. They can be used as a tool for assessment of the questionable conduct. Guidelines are consulted by courts because they provide evidence of standards justified in relation to evidence rather than custom, this helps the courts test the expert evidence that radically strengthen the normative dynamic of the law in actions alleging medical negligence. As clinical practice guidelines become more and more prevalent, some authors believe they will define the requisite "standard of care" for medical treatment and impact medical malpractice litigation. They may even replace expert testimony.