OBJECTIVES: To determine the prevalence and type of suboptimal pharmacotherapy that older veterans discharged from the emergency department (ED) or urgent care clinic (UCC) receive and to examine factors associated with suboptimal pharmacotherapy in this population. DESIGN: Retrospective, cohort study. SETTING: An academically affiliated Department of Veterans' Affairs (VA) Medical Center. PARTICIPANTS: Four hundred twenty-one veterans aged 65 and older who were prescribed a new medication at the time of discharge from the ED or UCC. MEASUREMENTS: The primary dependent variable, suboptimal pharmacotherapy, was a composite measure defined as one or more drug-related problems, based on drugs-to-avoid criteria, drug–drug interactions, drug–disease interactions, and failure to satisfy an explicit quality indicator for prescribing or medication monitoring. RESULTS: A total of 757 drugs were prescribed to the 421 patients at the time of discharge from the ED or UCC (mean number±standard deviation per patient 1.65±1.1). The most frequently prescribed medications were nonsteroidal antiinflammatory drugs (n=59), opioid analgesics (n=47), and fluoroquinolone antibiotics (n=46). Overall, 134 (31.8%) subjects were found to have suboptimal pharmacotherapy with regard to their discharge medications; 49 (11.6%) were prescribed a drug to avoid, 53 (12.6%) received a drug that introduced a new drug–drug interaction, 24 (5.7%) were given a drug that introduced a drug–disease interaction, and 74 (17.6%) did not have a quality indicator satisfied (61% of these evaluated prescribing and 39% evaluated medication monitoring). No consistent associations between patient or visit characteristics and suboptimal pharmacotherapy were identified in multivariable models. CONCLUSION: A substantial number of older adults discharged from the ED or UCC may be at risk for adverse events due to suboptimal prescribing and inadequate medication monitoring. Further study is needed to examine the relationship between suboptimal pharmacotherapy and adverse clinical outcomes. [ABSTRACT FROM AUTHOR]