The present study investigates the lost Apocalypse Commentary of Tyconius. Two manuscript fragments are extant while nine authors from the fourth to the eighth centuries directly cite the lost commentary in some cases extensively. Four conclusions follow the detailed study of the manuscripts and works influenced by Tyconius. First, the interdependence of the nine works influenced by Tyconius is demonstrated. Second, the manuscript tradition is reconstructed as far as possible. Third, the structure of the lost commentary is discussed. Fourth, a complete synopsis of the manuscripts and the passages quoted from the lost Apocalypse Commentary is presented.