A 1-year-old female infant presented with congenital giant, hairy and pigmented nevi. MRI scan as screening test revealed a cerebellar tumor. A diagnosis of provisional neurocutaneous melanosis was made on the basis of the patient's MRI and physical findings. At her 6 years of age, MRI revealed the tumor grown up to 3 cm diameter in 5 years. The cerebellar tumor was removed partially using the occipital transtentorial approach for tissue diagnosis. The color of the cerebellar tumor was whitish and contained neither benign nor malignant melanocyte. Pathological examination revealed diffuse astrocytoma. Finally residual cerebellar tumor was totally removed at a second surgical resection. To our knowledge, this is the first patient to be reported with astrocytoma complicated giant skin nevus except neurocutaneous syndrome cases.