It's well known that antibiotics are among the most widely used drugs in medicine. The administration of antibiotics in oral surgery offers a great deal, as far as the prevention of post-operative complications as well as the cure of infections diseases are concerned. Antibiotics, as all other drugs, in cases of improper use can cause harmful effects on the body. Antibiotics are used irrationally in dentistry and even more so in oral surgery for the cure of diseases which are not indicative or for the prevention of probable. As a result, there has been an increase in the frequency of their toxic side-effects plus the prevalence of resistant microorganisms. This paper describes the indications and side-effects of antibiotics in oral and maxillofacial surgery.