Neuronal ceroid lipofuscinosis (NCL) is one of the most common progressive neurodegenerative diseases seen in childhood. NCL is inherited as autosomal recessive trait, and is characterized by the accumulation of 'ceroid lipofuscin' in neuronal and extraneuronal cells. Clinical features include seizures, ataxia, myoclonus, loss of vision, and mental and motor deterioration. Although the disease is widely seen across the world, there seems to be an information gap in Asian countries. To date, no comprehensive and detailed studies on NCL have been carried out in Turkey. However, one could predict that the disease is rather frequent in Turkey due to high rates of consanguineous marriages. Thirty-six Turkish patients were evaluated in this study. Sixteen (44.5%) patients were girls, and 20 (55.5%) were boys. Parents were consanguineous in 25 families (80%). In five families (14%), the disease was seen in two sibs. The diagnosis was based on clinical evaluation, and neurophysiological, neuroradiologic, enzymatic, and histopathological studies. Electron microscopic study was the main diagnostic laboratory test.