Objectives Postpartum blues is known to be a major risk factor for postpartum depression and can be associated with the problems of language skills, behaviors or learning skills of their children. Therefore, it is very important for clinicians to evaluate precisely and control postpartum blues. Recent studies have found that music has an effect on depressive mood and the frontal EEG asymmetry of the patients with depression. The purpose of this study was to find out the effects of music on the frontal EEG asymmetry of the mothers with postpartum blues. Method Among one hundred and seventy mothers assessed with Korean version of the Edinburg Postnatal Depression Scale (EPDS), nine mothers with postpartum blues (EPDS ${geq}$ 10) as postpartum blues group and nine non-depressive mothers (EPDS < 10) as non-depressive mother group were included. Ten non-labored, non-depressive women were also included as a normal control group. The subjects were evaluated with the State Trait Anxiety Inventory (STAI)-X1, the Visual Analogue Scale (VAS) and the Depression Adjective Checklist-Korean version (K-DACL) and EEG twice before and after the music sesssion with the length of twenty minutes and thirty two seconds. The statistical analyses were done for A1 score (log R - log L) which were computed from the alpha powers at F3 and F4. Results No significant difference was noted in demographic data among all three groups. The postpartum blues group had higher scores in the STAI-X1, the VAS and the K-DACL compared to the other groups at baseline, and their A1 scores were lower than those of only normal controls. There was a statistically significant increase of A1 score only in the postpartum blues group after the music session. Conclusion This study suggests that the mothers with postpartum blues may have a frontal EEG asymmetry which is possibly associated with their depressive mood, and the music session can affect the frontal asymmetry positively.