Lithium carbonate has been recognized to induce several renal side effects, including the nephrotic syndrome. This is a report of an 11-year-old, prepubertal boy with a mood disorder treated with lithium who presented with edema, bilateral pulmonary effusions, proteinuria, and hypoalbuminemia. Renal biopsy revealed pathologic changes consistent with minimal change disease. These symptoms normalized after lithium discontinuation.