When associated with Multiple Sclerosis (MS), Trigeminal Neuralgia (TN) is often bilateral and more refractory to treatment. Carbamazepine is the first line of treatment for TN, however, common side effects of carbamazepine such as hyponatremia occasionally limit its use. We report the case of a 62 yr old female patient with a well controlled MS associated TN using carbamazepine. This drug needed to be discontinued because of recurrent symptomatic hyponatremia. Several agents including topiramate, gabapentine and amitriptyline were tried but none had any beneficial effect on TN. A small dose of eslicarbazepine (400 mg daily) provided excellent control of the TN pain on one hand and did not affect the plasma sodium levels on the other hand. Eslicarbazepine main advantage is providing the same effects of carbamazepine or oxcarbazepine but with an incidence of hyponatremia of less than 1%. It is much safer to use when the risk of hyponatremia is increased. To our knowledge, this is the first case that reports the use of eslicarbazepine in one of the several indications of carbamazepine such as pain and mental health problems. Eslicarbazepine use in epilepsy was reported extensively. We feel that a therapeutic trial of eslicarbazepine is justified when either carbamazepine or oxcarbazepine have to be discontinued because of hyponatremia despite their efficacy.