This study was performed for the determination of the time and temperature correlation when using API 20 E system for the identification of Yersinia ruckeri. 15 strains from different origins were incubated at 20, 22, 25 ºC and for 24, 48, 72 hours. Totally nine different incubation options were checked and correlated with the conventional methods. As a result, API 20 E system could be used at 20ºC for 72 hours; at 22 ºC for 48 hours or at 25 ºC for 24-48 hours to give the best results.