Thyroid storm, or thyrotoxic crisis, is a rare but well-described and potentially lethal exacerbation of thyrotoxicosis, characterized by multisystem effects due to failure of the hypothalamic-pituitary-thyroid axis. Thyroid storm is seen most frequently in the setting of inadequately treated Graves disease; however, it may also be triggered or exacerbated by infection, trauma, childbirth, radioiodine treatment, and pharmacologic agents. While there are rare reports of cases in which illicit drug use may have triggered or exacerbated thyroid storm, none specifically involving synthetic cannabinoids have been previously described. We present the case of a 25-year-old man who presented with thyroid storm in the setting of poorly controlled Graves disease and synthetic cannabinoid use.