The incidence of pneumonia is higher in older than younger people, due to both an increase in factors facilitating entry of infectious agents into the lungs, and attenuated functioning of the immune system. Classic features of presentation of pneumonia may be absent. The most common signs of pneumonia in old age are tachypnoea and tachycardia. Aetiology is established in only 50% of older patients. The empirical treatment of community-aquired pneumonia (CAP) should be aimed at its most common cause, Streptococcus pneumoniae. The empirical treatment of health care-associated pneumonia (HCAP) should be targeted at Gram-negative agents. Choice of antibiotic must include consideration of potential drug interactions.