The pre-travel medical evaluation of elderly patients and patients with chronic illness requires special assessment and advice. Screening and special precautions are reviewed for traveling patients with respiratory disease, cardiac disease, sinusitis, diabetes mellitus, HIV infection, and other chronic medical conditions. Current guidelines for empiric therapy and prophylaxis of travelers' diarrhea are reviewed, with emphasis on concerns in geriatric or chronically ill travelers. Special considerations such as potential drug-drug interactions and insurance coverage are also discussed.