Clinical symptoms and radiologic characteristics of gliomatosis cerebri (GC) are non-specific and the condition may be confused with other central nervous system diseases. We report three patients with GC; all the three patients had involvement of more than three lobes and the deep white matter, as well as bilateral involvement. Differentiation of GC from other neurologic diseases involving diffuse white matter may be difficult. However, the diagnosis can be based on the combination of radiologic and histopathologic features.