According to the World Health Organization, the prevalence of multiple sclerosis (MS) in Iran is 4 in 100,000. One of MS manifestations is peripheral facial palsy. There has not been any study of the prevalence of facial palsy secondary to MS in Iran. Therefore we conducted a retrospective descriptive analytical cross sectional study in which we reviewed the medical records of all patients diagnosed with MS who visited the neurology clinic between years 1991 and 2007. One thousand and sixty nine patients were studied and among them 53 patients (5%) had isolated facial palsy. In 22 patients (2.1%), isolated facial palsy occurred as the first MS clinical manifestation. In these patients, the interval to the second neurological symptom was 52 months. We compared the occurrence of other neurologic manifestations in patients with and without facial palsy. Facial numbness, internuclear ophthalmoplegia, gustatory disturbance and pyramidal disorders were significantly more prevalent in patients with facial palsy. In conclusion, isolated facial palsy occurs in about 5% of MS patients in Iran. It may rarely be the presenting feature of MS.