Retinoic acid has been used as a trial of chemotherapeutic agent in the field of cancer therapy and resulted some success in leukemia and breast cancer. Recently, it is being tried on the malignant astrocytoma. We evaluated the effect of all-trans and 13 cis-retinoic acid on C6 cell line cultures(14 day incubation) using MTT assay and counting of cell numbers for establishing the basis of clinical trial. The cell number counting showed 51.6% and 43.1% of control in the cell number at 10-6M concentration of all-trans and 13 cis-retinoic acid. MTT assay showed 56.4% and 46.1% of control in the optical absorbance at 10-6M concentration of all-trans and 13 cis-retinoic acid. These results indicate the possiblity of both drug as effective chemotherapeutic agents for glial cell tumors but in-vivo study will be needed for clinical trial.