OBJECTIVES: Medications with anticholinergic properties are frequently associated with severe adverse events in the elderly, and therefore highly anticholinergic agents are considered potentially inappropriate in this population. The objectives of this study were to determine the prevalence and predictors of prescribing potentially inappropriate anticholinergic medications among elderly patients in ambulatory settings. METHODS: This study involved analyses of visits by elderly patients (>65 years) in office-based settings from 2009 public use data files of the National Ambulatory Medical Care Survey (NAMCS). The revised 2012 American Geriatrics Society (AGS) Beers criteria were used to identify potentially inappropriate anti­cholinergic medications. Descriptive analysis was conducted using sampling weights to determine the prevalence of visits involving inappropriate anticholinergic medications irrespective of diagnosis. Multiple logistic regression within the framework of Andersen Behavioral Model (ABM) was used to determine the predictors of potentially inappropriate anticholinergic medications in the elderly. RESULTS:  A total of 279.5 million visits (26.93% of all clinic visits) to physician offices in 2009 involved elderly patients. Approximately 13.33 million visits (4.77% of all clinic visits by the elderly patients) involved at least one potentially inappropriate anticholinergic medication. The most frequently used anticholinergics were antihistamines followed by antispasmodics and skeletal muscle relaxants. Factors positively associated with inappropriate anticholinergic prescribing were female gender, major reason for visit, number of medications prescribed and specialty. Factors negatively associated with inappropriate anticholinergic prescribing were age, total number of chronic conditions and region. CONCLUSIONS:  Nearly one in twenty visits by the elderly involved prescribing of potentially inappropriate anticholinergic medications. These prescribing patterns raise quality of care concerns owing to the significant adverse events associated with their use in the vulnerable population.