Mirtazapine is an antidepressant approved for the treatment of major depressive disorder. It has been reported to also stimulate appetite and/or increase body weight, which may be beneficial in certain patient populations such as the elderly. To evaluate the use of mirtazapine and other antidepressants in underweight older adults, a retrospective chart review of patients (60 years of age or older and with a body mass index < 22 kg/m2) who were prescribed an antidepressant during hospitalization was conducted over a six-month period at a large university teaching hospital. Results demonstrated that underweight older patients were more likely to receive mirtazapine than any other antidepressant, prompting a systematic literature review to assess its potential role in appetite stimulation and weight gain. In addition, educational inservice training for health care professionals within the institution was provided to discuss the management of weight loss and appetite suppression in the elderly as well as the potential benefits and risks of antidepressant therapy in older adults.