Subacute sclerosing panencephalitis is a rare, slow viral infection caused by a defective measles virus. Although it is a rare disease, it is still important in developing countries. The onset is generally between the ages of 5-15 years. We reported the clinical and laboratory profile and nature of 9 patients under the age of 4 years with SSPE. Although it is known that a few patients with SSPE have an acute and rapidly fulminating course, in this study rate of progression was rapidly progressive in 6 patients and progressive in 3 of them on admission. Unfortunately, 4 of them were lost to follow up because of address and/or telephone number alterations. Although the number of patients in this study is not sufficient, we suggest that SSPE patients under the age of 4 years have a poor prognosis as a result of progressive or rapidly progressive course despite medical treatment.