The purpose of this study was to establish the inter-rater reliability of the modified Trunk Impairment Scale (mTIS) for stroke that translated into Korean in chronic stroke patients. The subjects participated in this study were forty-eight stroke patients with hemiparesis. The mTIS scale was administered in 2 testing sessions 3 days apart. Inter-rater reliability (intraclass correlation coefficient ICC2,1), Internal consistency and Kappa coefficient was used to examine the level of agreement between raters. Absolute reliability indices, the standard error of measurement (SEM), and the Minimal Detectable Change (MDC). The item-to-total correlation was examined by correlating the total score of mTIS to the individual item of mTIS. The mTIS meets the following requirements: (1) The percentage agreement of these items ranged from 69%~79%, item-to-total correlations were all significant, ranging from r=.63~.86 (p<.01). (2) The Kappa coefficient of the 1~3, 6 items of mTIS ranged .41~.58, the 4, 5 items were .62, .64. mTIS showed good internal consistency (Cronbach’s α of 0.81). Inter-rater reliability was good for mTIS(ICC2,1=0.90(0.83~0.94)), SEM and MDC were 1.07, 2.97. mTIS was a reliable assessment tool of trunk performance for patients with stroke, it could be a useful tool to evaluate the compensation move ment without ceiling effect.