BACKGROUND: Migraine can cause suffering and reduce functioning and productivity. Migraine is usually suboptimally treated, with many migraineurs not being satisfied with the applied acute treatment. Migraine-ACT is a four-item assessment tool used by clinicians to identify patients who require a change in their acute treatment. The objective of this study was to determine validity and reliability of the Korean Migraine-ACT. METHODS: Participants who visited Hallym University Sacred Heart Hospital neurology clinic for headache were recruited. The survey employed SF-36, HIT-6, and Migraine-ACT. Headache diagnosis was assigned on ICHD-II after completing a semistructured diagnostic interview. RESULTS: A total of 52 migraine patients aged 38.7+/-14.7 years (mean+/-SD) were recruited. There was a positive correlation between general summary scores on SF-36 and Migraine-ACT (Spearman's correlation coefficient=0.39, p<0.05) and a negative correlation between HIT-6 scores and Migraine-ACT scores (Spearman's correlation coefficient=.0.52, p<0.05). Cronbach's alpha of Migraine-ACT was 0.78. CONCLUSIONS: These results indicate that Korean Migraine-ACT is a valid and reliable instrument to identify migraine patients who require a change in their acute treatment.