Purpose The purpose of this study was to investigate the reliability with which static and dynamic balance can be measured using a smartphone. Methods Sixtynine people participated in the study. The smartphone attached to the lower back and tibia. The gyroscope value indicated the dynamic balance ability, and the acceleration value indicated static balance ability on the stable ground and the unstable balance pad. Balance abilities were measured two times at oneday intervals between tests and retests. Results On the stable ground, the acceleration value of the tibia showed a high correlation (r>0.70, p<0.05), and the gyroscope value of the tibia showed a moderate correlation (r>0.50, p<0.05). The acceleration value of the lower back showed very high correlation (r>0.90, p<0.05), and the gyroscope value of the lower back showed a high correlation (r>0.70, p<0.05). On the unstable balance pad, the acceleration value of the tibia showed a high correlation (r>0.70, p<0.05), and the gyroscope value of the tibia showed a high correlation (r>0.70, p<0.05). The acceleration value of the lower back showed high correlation (r>0.70, p<0.05), and the gyroscope value of the lower back showed a very high correlation (r>0.90, p<0.05). All the measurements showed very high agreement (ICC>0.75). Conclusion As a result of this study, it was confirmed that the smartphone can be usefully used as devices for the balance ability.