Reversible posterior leukoencephalopathy syndrome (PLS) is characterized by headache, clouding of sensorium, visual disturbances and seizures. It is associated to hypertension, renal disease or immunosuppressive therapy. We report three males, aged 9, 12 and 16 years and one female, aged 5 years wih PLS associated to immunosuppressive therapy. All had seizures and three had headache and clouding of sensorium. One case was associated to an hypertensive emergency, one to liver failure and one to high tacrolimus levels. Magnetic resonance imaging showed lesions in the white matter in two patients and in the gray matter in the other two. The lapse between the start of immunosuppressive treatment and neurological symptoms ranged from 4 days to 6 months. All received antiepileptic drugs and immunosuppresive therapy was changed or decreased, with complete clinical recovery (Rev Méd Chile 2008, 136: 93-8)