This article describes a 6-week study evaluating body sway during double-blind therapy with nortriptyline versus paroxetine in geriatric patients. Body sway was measured with patients' eyes open, then closed, using a stable force platform at 4 timepoints: before starting antidepressant medication, and after 1, 2, and 6 weeks of treatment. Measures such as the length (L) of path of the center of pressure (COP) and the area included within the COP path were selected for quantitative assessment of stability. A repeated measures analysis of variance (ANOVA) model with planned comparisons was used to examine the pair-wise difference at baseline and Weeks 1, 2, and 6 of treatment. No significant difference was found in body sway parameters over the 6 weeks of study for patients treated with either nortriptyline or paroxetine.