The commercially available auto-injector epinephrine is considerable expensive. Epinephrine prefilled syringe is an alternative treatment for anaphylaxis patients. The objective of the present study was to evaluate the stability and sterility of epinephrine prefilled syringe. Epinephrine prefilled syringe was kept in the pencil box to prevent from light exposure. The active ingredients, integrity and level of potency were measured by high-performance liquid chromatography (HPLC). The sterility was accessed by aerobic bacteria and fungi culture. The epinephrine concentration at 1, 2 and 3 months after the preparation was 101.36, 99.31 and 101.09%, respectively (acceptable range 90 - 110%). The pH was 3.17 - 3.23 (acceptable range 2.8 - 3.6). Nor-epinephrine was undetected. The cultures for bacteria and fungus were both negative. Consequently, epinephrine prefilled syringe was stable and sterile at least three month after preparation. Epinephrine prefilled syrine is an alternative low cost treatment for anaphylaxis patient.