Neuronal ceroid lipofuscinosis (NCL) is a lysosomal storage disorder that causes progressive neurodegenerative disease as a result of storage in neurons and other cells. Late infantile type (NCL Type 2) of NCL, which is the most common neurodegenerative disease in childhood, is characterised by a homozygous mutation in the tripeptidyl peptidase-1 (TPP-1) gene. A male infant was referred to our neonatal intensive care unit (NICU) on 26th day of life with a diagnosis of metabolic disease. He was intubated. He was hypotonic and newborn reflexes were not present. Cranial magnetic resonance (MR) imaging revealed severe atrophy and delayed myelination of cerebellum and cerebral hemispheres. A novel homozygous pathological mutation was detected in exon 9 of the TPP-1 gene. With this case, it should be kept in mind that NCL may rarely start early in neonatal period and should be suspected in newborns with cerebral and cerebellar atrophy for early diagnosis. Key Words: Hypotonia, Lysosomal storage diseases, Metabolic disease, Neuronal ceroid lipofuscinosis, Newborn.