In patients with an acceptable pathological diagnosis of Kufs disease, two major forms have been identified: Type A presenting as progressive myoclonus epilepsy around the age of 30, and Type B presenting in the same age range with dementia as well as cerebellar and/or extra-pyramidal signs. In adolescence, two subgroups of neuronal ceroid-lipofuscinosis (NCL) emerge. The first group consists of patients resembling either type A or B Kufs disease, but with earlier onset (20% of all cases). These must be distinguished from the second group of rare patients with protracted juvenile NCL presenting with early and prominent visual failure. Although Kufs disease is rare, diagnosis during life should now be possible. The advantages, techniques, and pitfalls of biopsy diagnosis are presented by Carpenter et al. [1988]. We believe that delineation of these two clinical syndromes should aid in the identification of other possible cases of Kufs disease, leading to appropriate pathological examinations to confirm the diagnosis. Knowledge of whether this clinical distinction is biologically meaningful must await the discovery of the more fundamental biochemical defects.