BACKGROUND Neuronal ceroid lipofuscinoses (NCL) is a group of degenerative neurological diseases. The diseases are autosomally recessively inherited and are characterized by the accumulation of fluorescent ceroid and lipofuscin in neuronal cells in the brain and in extraneuronal cells. The aim of this review was to assess and to summarize research related to diagnostics and treatment of NCL. METHODS The article is built on own experience and systematic searches on PubMed, Medline, PsychInfo and the Internet. CONCLUSIONS Three main types of NCL with childhood onset are recognised; an infantile, a late infantile, and a juvenile type. One NCL type starts in adulthood. In Norway the juvenile type is diagnosed most frequently. The diseases are rare. The incidence rates in different countries range from 0.5 to 8.0 per 100,000 live births. The main features include impaired vision, failure of psychomotor development, seizures and premature death. Prior to availability of genetic testing, the clinical status, ophthalmologic examination, examination of blood cells for deposited material (vacuolised lymphocytes) and neurophysiological examinations were the most important methods of confirming the diagnosis. Recent genetic findings have established that defects in at least six different genes underlie the various forms of NCL. There is no curative treatment. Scientists are trying to develop treatment using enzyme replacement, gene therapy, stem cell transplantation and pharmacotherapy. Symptomatic and palliative treatment is therefore essential.