We examined the alteration and expression of c-myc protooncogene in 11 human intracranial meningiomas using Southern blot, Northern blot and immunohistochemical techniques. Southern blot showed neither amplification nor rearrangement but Northern blot and immunohistochemical study revealed enhanced expression of the c-myc gene. Immunohistochemically, c-myc product was found in all of the 11 cases and seven of these cases showed an above moderate degree of immunoreaction in semiquantitative analysis. Loss of heterozygosity at IGLC2 locus on chromosome 22 was detected in four of the 8 informative cases. But extent and intensity of immunoreactivity did not correlated with loss of heterozygosity on chromosome 22. These genetic changes may play important roles in the pathogenesis of human intracranial meningioma.