The efficiency of excited-state interaction between Sm³⁺ and the industrial product Favipiravir (Fav) has been studied in different solvents and various pH values. The results indicated high luminescence intensity peak at 645 nm of Samarium complex in DMF without any change in solvent pH value. The photophysical properties of the Emissive Sm³⁺ Complex have been elucidated, the Samarium was used as optical sensor for the assessment of Fav in the pharmaceutical tablets λ_ex=370 nm with a concentration range (16-600) µg/mL of Fav, correlation coefficient of 0.97 and detection limit of 8 µg/mL. This method is simple, accurate and can successfully be applied to the determination of Fav in pharmaceutical preparation samples with remarkably satisfactory results.