Darier's disease, an autosomal dominant genodermatosis, arises from a mutation in the ATP2A2 gene that codes for sarco/endoplasmic reticulum Ca2+-ATPase in the endoplasmic reticulum and is characterized by greasy keratotic papules commonly found in seborrheic regions. Conventional treatments, including topical corticosteroids, antibiotics, antifungals and retinoids, often have limited efficacy. The present article reports the novel use of oral magnesium chloride supplementation (300 mg daily) in the treatment of Darier disease. After 5 years of limited improvement using conventional therapies, significant improvements in neck lesions were observed within 1 month of starting oral magnesium chloride. This suggests that oral magnesium chloride may be an effective therapeutic option for Darier disease, although further in vitro and clinical trials are necessary to evaluate its clinical efficacy.