Symptoms of infection in the elderly may be absent, vague or atypical. Infection should be suspected when an elderly patient presents with a decline in well-being or with non-specific symptoms such as falls, dizziness, confusion, anorexia or weakness. Common infections include bacterial pneumonia, urinary tract infection, intra-abdominal infections, gram-negative bacteremia and infection of decubitus ulcers. Antibiotic therapy is not recommended for asymptomatic bacteriuria or locally infected decubitus ulcers. Drug dosages should be adjusted for the age-associated decline in renal function and for hepatic or renal insufficiency. The trend in antibiotic therapy is evolving toward the use of third-generation cephalosporins instead of aminoglycosides to avoid the side effects of nephrotoxicity and ototoxicity. Pneumococcal, influenza and tetanus/diphtheria immunizations help prevent morbidity and mortality.