Two important drugs griseofulvin and dexamethasone have been quantitatively estimated through complexation with fluoranil (tetrafluoro-2,5-cyclohexadiene - 1,4- dione). The optimal experimental conditions, applicability of the suggested method to assay the cited drugs in their tablet forms, and statistical analysis of the results were studied. The results obtained were compared with those of the corresponding official method of assay for each drug, showing good agreement with the official methods. Furthermore, the reaction products have been isolated and subjected to structure elucidation by means of IR-Spectroscopic technique.