Cefazolin is a first-generation cephalosporin antibiotic. Cefazolin is mainly used to treat bacterial infections of the skin. It can also be used to treat moderately severe bacterial infections involving the lung, bone, joint, stomach, blood, heart valve, and urinary tract. It is clinically effective against infections caused by staphylococci and streptococci of Gram-positive bacteria. These organisms are common on normal human skin. Resistance to cefazolin is seen in several species of bacteria. Cefazolin is extensively used as prophylaxis antibiotic before wide range of surgical operations. Cefazolin is a broad spectrum antibiotic and can be used to treat different types of infections including urinary tract, skin, and bone infections. The following represents MIC susceptibility data for a few medically significant bacteria. Adverse drug reactions from cefazolin are not common.