Low-cycle fatigue tests were performed on reinforcing bars in order to assess the acceptability of newly developed high-strength reinforcing bars in seismic applications. The steels tested are classified as grade 60 A706, grade 80 A706, grade 80 A615, and grade 100. The high-strength reinforcing bars tested represent the two most common manufacturing processes used today: microalloying and quenching-and-tempering. The results of these tests are presented along with comparisons between the fatigue life of bars based on steel grade and other bar properties. A statistical analysis of the test results is presented in order to assess the impact of many parameters on the low-cycle fatigue performance of grade 60 A706 and higher-strength reinforcing bars.