Tetanus toxin production with high yield by a fermentor system was performed and with this new developed process, pilot adsorbed tetanus vaccines were produced. Tetanus toxin eluted from 5 days culture of Clostridium tetani strain Harvard 49205 in 300 L medium in fermentor system was consentrated, then toxoid form prepared from this toxin was adsorbed onto aluminum hydroxide gel (alhydrogel) after purification. The new adsorbed vaccine at pilot level was produced on lot base and the control tests according to the WHO requirements were performed for each lot. The potency tests were repeated at different time intervals for >3 years for some lots by mouse toxin challenge assay. During that time period, the adsorbed vaccines passed successfully from all the tests and they were evaluated as stable and potent.