OBJECTIVES: This study examined the prevalence of antidepressant drug use and factors associated with their use among elderly nursing home residents in the Unites States using the 2004 National Nursing Home Survey (NNHS) data. METHODS: The study involved analysis of prescription and resident files of a nationally representative sample of residents aged ≥65 years from the 2004 NNHS data. The analysis focused on the prescribing of any antidepressant, including selective serotonin reuptake inhibitors (SSRI), tricyclic antidepressants (TCAs), serotonin modulators, serotonin-norepinephrine reuptake inhibitor (SNRI), MAO (Monoamine oxidase) inhibitors and ‘other’ antidepressants such as mirtazapine and bupropion. A descriptive weighted analysis was performed to examine the prevalence patterns. Multiple logistic regression within conceptual framework of Andersen’s Behavioral Model was used to examine the predisposing, enabling and need characteristics associated with antidepressant use. RESULTS: The overall prevalence of antidepressant use was found to be 46.22% (95%CI, 45.16-47.27). The most prescribed class of antidepressants was SSRIs (67.29%), followed by serotonin modulators (10.05%), SNRIs (6.02%), TCAs (5.06%) and MAO inhibitors (0.02%). Citalopram (28%) was the highest prescribed individual antidepressant followed by mirtazapine (22.05%). Among the predisposing characteristics, age, race, and marital status were significantly associated with antidepressant drug use. Enabling factors like Medicare or Medicaid payment source and facility bed capacity predicted antidepressant use. Among need characteristics, likelihood of receiving antidepressant prescription decreased with increased dependence in decision making ability and out of bed mobility. Also presence of depressed mood indicators, history of falls and fractures, and an increase in number of medications prescribed had positive association with antidepressant prescription.  CONCLUSIONS: Nearly half of elderly nursing home residents received antidepressants. Predisposing, need, and enabling factors played important roles in use of antidepressants. Overall, the study findings suggest that antidepressant treatment is highly prevalent in nursing homes possibly due to increased recognition of symptoms in the elderly population.