Older adults experience more chronic illnesses than any other age group (Merck Research Laboratories, 1997) and thus are frequently exposed to several types of medical information, including treatment recommendations, medical advertisements, and instructions for using medications and home medical devices. The present chapter considers how older patients acquire and use medical information across a wide range of real-world contexts. Of particular interest is how older patients comprehend and remember complex dietary and drug regimens as well as medical claims and instructions for use of medical technologies, despite facing numerous challenges (i.e., sensory, cognitive, biomedical, and psychosocial) in processing this information. A more complete understanding of how older adults process health information should result in greater treatment compliance,