This study examines whether or not in Sturge-Weber syndrome hypoperfused brain areas that are affected by calcification continue to retain some function and participate in language and motor activations. [15O]-Water positron emission tomography (PET) was used for brain mapping of these functions in two patients with extensive unilateral calcification and hypoperfusion and in one patient with calcification and hypoperfusion restricted to the left posterior region. Task-related regional cerebral blood flow changes suggest that (1) hypoperfused areas may become activated during language and motor performance, and (2) progressive calcification in Sturge-Weber syndrome is associated with functional reorganization in the language and motor domains. Interhemispheric reorganization appears to be more pronounced for language than for motor functions.