We describe the unusual clinical course in a case of exanthema subitum with affection of the liver and central nervous system in a 10-months-old girl. HHV-6 infection was confirmed serologically (positive HHV-6 IgM from 10th to 29th day, increasing IgG-titres). At the beginning of the illness convulsions with preference to the right side were noticed, which were consistent with an encephalitis (on top to a suspected pre/perinatal lesion) and resulting in spastic triplegia. Nuclear magnetic resonance imaging and cranial computertomographic results showed severe, predominantly left-sided cerebral lesions. In addition there was clinical and biochemical evidence of an associated hepatitis. Human herpesvirus-6 has been identified as the cause of exanthema subitum. In addition, the virus is known to cause other clinical entities (lymphadenopathy, febril seizures, hepatitis, postinfectious chronic fatigue a.o.) and has been identified in brain tissues. Our observations show that the course of exanthema subitum can be complicated by affection of the liver and central nervous system. At present it is impossible to estimate the clinical outcome in our patient.