A 65-year-old patient presented with grey-brownish maculae localized on the face. He had been treated with oral terbinafine due to onychomycosis, and the first spots manifested after 4 weeks of therapy. Other drugs were not taken by the patient, who was otherwise in a healthy condition. Histology showed melanin localized within macrophages in the upper and lower dermis. Cutaneous side effects are well described in patients treated with terbinafine and usually present as urticaria or eczema. Severe reactions may occur in rare cases. Hyperpigmentation has not yet been described as a consequence of oral terbinafine. Grey hyperpigmentation as it occurred in our patient has been described as a side effect of therapy with minocycline, amiodarone, tricyclic antidepressants, or heavy metals. This case report shows that drug-induced hyperpigmentation should also be considered if the patient takes drugs not known for this kind of side effect.