Vaccines are one of the most successful medical advances in modern times. Most vaccine-preventable illnesses are unfamiliar to modern parents. Because of this, parents are increasingly questioning the necessity of immunizing their children, especially because no vaccine is completely free of adverse effects or the risk of complications. Family physicians should be aware of the risks and benefits of recommended immunizations. Thimerosal is currently used only in multidose vials of influenza vaccine, and exposure through vaccines is not associated with adverse neurologic outcomes. The measles, mumps, and rubella vaccine is not associated with autism. Vaccines are associated with local reactions, such as pain and erythema. The rotavirus vaccine minimally increases the rate of intussusception, whereas other vaccines minimally increase the risk of syncope. Although immunization with the human papillomavirus vaccine is recommended for all boys and girls, vaccination rates remain low. Physicians should guide parents to credible resources if they are considering vaccine refusal. If a recommended vaccine is refused, proper documentation is essential. The Vaccine Adverse Event Reporting System and National Vaccine Injury Compensation Program track adverse events and allow compensation for documented harms from vaccinations.