Beta-lactams are generally safe drugs and serious adverse events are rare and allergy is overdiagnosed. Accurate diagnosis can usually be achieved through careful history and in some instances skin or in vitro testing is required. Even among individuals with true immediate-type allergy to penicillin, most cephalosporins are readily tolerated and desensitization is usually an option in cases where no alternate antimicrobials are available. Other allergic reactions (Type II, III and IV) are rare and avoidance of the culprit agent is generally recommended. Nonallergic or morbilliform rashes are generally not allergic in nature and should not prompt drug or class avoidance. Other adverse events are frequently dose-related and can be avoided by appropriate dosing and consideration of renal function.