Introduction: Meningiomas are predominantly benign tumors, which arise from the arachnoids’ cap cells. The development mechanism is unknown but they may result from an adverse effect of cranial irradiation and trauma. Antigen KI-67 also known as Ki-67 or MKI67 is a protein that in humans is encoded by the MKI67 gene (antigen identified by monoclonal antibody Ki-67). The antigen KI-67 is a nuclear protein that is associated with and may be necessary for cellular proliferation. Inactivation of antigen KI-67 leads to inhibition of ribosomal RNA synthesis. Ki-67 is an excellent marker to determine the growth fraction of a given cell population, the fraction of Ki-67-positive tumor cells (the Ki-67 labeling index) is often correlated with the clinical course of cancer. Materials and Methods: This is a cross-sectional study that had been performed at the National Center for Neurological Sciences during February 2011 to December 2013. The study included samples from intracranial meningioma patients histologicaly diagnosed at the National Center of Neurological Sciences, during the above mentioned period. The study was conducted in accordance with the guidelines of the local ethical committee. For immunohistochemistry, all meningioma tumors at Elhassan Medical Laboratory for histopathology and cytology during the above mentioned period were processed for ki 67 antigen. Results: Positive immmuno-staining for Ki67 was identified in 88% of the patients. Labelling indexes of 11-20% were reported in 40% of the Ki 67 group. Mostly in fibrous and atypical subtypes of meningioma.