This chapter discusses the ailments and diseases associated with the frail and older patients and their treatment. The ten most common diseases in elderly are—hypertension, cataract, osteoarthritis, chronic obstructive pulmonary disease, ischemic heart disease, diabetes, benign prostatic hypertrophy, dyspepsia, constipation and depression. Assessment of the elderly follows the same principles of clinical evaluation as for any age group. The components of geriatric assessment are physical, functional, psychological (cognitive, affective), financial, social support and care facility, environmental and overall quality of life. The one chief complaint approach is not applicable to older patients, and a system of prioritized complaints has to be developed. The examiner should differentiate the problems into treatable and untreatable problems. Geriatric assessment requires the involvement of experts from various disciplines, namely, physician, social worker, nurse, physiotherapist, occupational therapist, dietician and pharmacist.