Lithium is widely used, and most of its side effects are well established and recognized. Persistent neurologic sequelae or dysfunctions are not common, but they are serious side effects. They usually persist after acute toxicity following accidental or suicidal overdose or during maintenance therapy, when toxicity is more insidious. The irreversible neurologic sequelae are generally cerebellar signs, especially ataxia and dysarthria. Risk factors are sometimes present and recognizable, but more often they are not well identified. Persistent neurologic handicaps greatly reduce the quality of life and are difficult to manage. Lithium toxicity can be avoided by conservative prescribing, care in combining drug therapies, and, above all, educating the patient and caregivers to recognize early signs of the condition. A review of the literature is presented, together with vignettes of a further seven cases.