Today, it is very important to evaluate fatigue symptoms in young adults. The subjective symptoms index (SSI) has been widely used to evaluate fatigue, but it was developed to evaluate fatigue in laborers and has various associated problems. Therefore we developed a new subjective fatigue scale (SFS-Y) consisting of 24 items, to evaluate fatigue in young adults. The purpose of this study was to clarify the features of the SFS-Y and compare them with those of the SSI.Both instruments were administered to 595 students aged 15-20 yr, and the main results obtained were as follows. The SFS-Y has more items related to mental fatigue and measures fatigue parameters that are different from those of the SSI. Also the SFS-Y has more sub-scales than the SSI and is a better multiple evaluator, including evaluations of gender differences. Although both the SFS-Y and SSI have acceptable levels of reliability, that of the SFS-Y is somewhat higher. Furthermore, the SFS-Y can better measure slight changes in subjective symptoms of fatigue occurring during daily activity. These observations suggest that the SFS-Y is effective as a measure of subjective fatigue symptoms in young adults.