Autoimmune limbic encephalitis is an increasingly recognised cause of cognitive decline and confusion. The typical presentation is with subacute cognitive decline, behavioural disturbance and seizures. Magnetic resonance imaging may show characteristic changes in the medial temporal regions. The diagnosis is confirmed by identification of elevated voltage-gated potassium channel antibody (VGKC-Ab) titres. It is a highly treatable condition, often responding well to intravenous immunoglobulin or steroids. Recognition of autoimmune limbic encephalitis is sometimes delayed--usually because the diagnosis has not been considered--which can result in long-term neurological consequences.