Olanzapine is a second-generation antipsychotic (SGA) that has been shown to promote disease remission in persons with treatment-resistant depression when used in combination with fluoxetine. However, tolerability of treatment augmentation with SGAs may be limited because of common adverse effects, such as weight gain, hypertriglyceridemia, and elevated glucose. Data exist pertaining to rare localized edematous reactions or angioedema with use of SGAs, but diffuse whole-body edema has yet to be documented. A 47-year-old white female with treatment-resistant depression presented with a 5-day history of weight gain and swelling of her torso and extremities. Five days prior, she had initiated olanzapine/fluoxetine 6/50 mg daily following failure of fluoxetine 40 mg daily monotherapy. The patient was noted to have gained 3.6 kg since her last appointment and exhibited profuse pitting edema on her forearms, lower limbs, hands, and chest. Olanzapine/fluoxetine was discontinued and the patient was prescribed a 3-day course of a loop diuretic for symptomatic management. A follow-up visit 5 days later noted complete resolution of symptoms. Because of the temporal relationship of symptoms with initiation of olanzapine, we recommend monitoring for edema with initiation and/or titration of therapy.