Background: Astrocytomas are a heterogenous group of primary CNS tumors, Glioblastoma multiforme (GBM), grade IV is particularly aggressive. Most patients diagnosed with this tumor die within one year of the diagnosis and 5% only survive more than 5 years despite aggressive therapy. Aim: assessment of cyclooxygenase 2 expression in various grades of astrocytomas and correlation with other clinical and histopathological variables, for prognostic or therapeutic implications. Materials and methods: 40 cases of archived paraffin blocks of various grades of astrocytoma were tested for cyclooxygenase 2 expression by immunohistochemistry using a mouse monoclonal antibody against human Cyclooxygenase 2. Results: COX-2 expression was detected in 38 (95%) of 40 astrocytomas with an increased percentage of tumor cells expression (strong positive expression) in grade III (100%) & grade IV (83%) cases as compared to grades I & II cases that showed higher percentage of weak positive expression, while two cases of Grade I astrocytoma had negative Cox 2 expression (p value= 0.0114), i.e. tumors with higher rate of cell proliferation tended to have increased expression of COX-2, but did not show significant difference among patient age, sex and tumor location. Conclusion: COX-2 is up-regulated in the majority of high-grade astrocytomas and may contribute to astrocytic tumorigenesis and COX-2 inhibitors may have a potential role as an adjuvant therapy of astrocytic tumors.