PURPOSE: This study investigated whether interval walking training (IWT) improves cognitive function and arterial function in older adults. METHODS: A total of 68 older adults registered in clinical trials (mean age ± standard deviation, 70 ± 4 years) were randomly assigned to two groups: one group performed IWT (n = 34), and the other performed normal walking training (NWT, n = 34). Participants in the IWT group performed five or more sets of low-intensity walking (duration: 3 min per set; peak aerobic capacity for walking: 40%) followed by high-intensity walking (duration: 3 min per set; peak aerobic capacity for walking: > 70%). The NWT group walked at approximately 50% of the peak aerobic capacity for walking. The IWT and NWT were performed for 20 weeks. Trail making test-A and B and carotid-femoral pulse wave velocity (cfPWV) were measured in both groups at baseline and again at the end of the 20-week study period. RESULTS: Compared to baseline, time for trail making test-A (IWT group: P = 0.00004, NWT group: P = 0.000006) and B (IWT group: P = 0.03, NWT group: P = 0.003) as well as cfPWV (IWT group: P = 0.000002, NWT group: P = 0.03) decreased significantly after the 20-week study period in both groups. However, cfPWV in the IWT group decreased significantly more than that in the NWT group (P = 0.03). CONCLUSION: These results suggested that although both IWT and NWT were similarly effective at improving cognitive function, IWT reduced central arterial stiffness more than NWT.