Identifying the function of behavior is crucial in formulating functionally-based treatment programs for people with challenging behaviors. The Questions About Behavior Function (QABF) is a well-established instrument with sound psychometric properties. The present study describes the development process for a Korean version of the QABF. The factor structure was examined in a sample of 153 QABF-K assessments, which yielded a five-factor-solution identical to the original English version. In terms of reliability, internal consistency was good with Chronbach's alpha ranging from 0.80 to 0.87 and test-retest reliability was found to be good with correlation coefficients ranging from 0.73 to 0.91. Based upon the present results, the QABF-K appears to be a promising tool for use with informants whose primary language is Korean. (Contains 3 tables.)