Objectives : The purpose of this study was to develop the Korean version of the Social Functioning Scale (KSFS) in the patients with schizophrenia. Methods : KSFS was administered to 90 schizophrenic patients and 80 their parents and 90 normal controls for examining the reliability and validity. Results : Data analysis showed statistically significant reliabilities and validities of KSFS. The test-retest reliability, rater vs. self-report reliability, and internal consistency for total scores of KSFS were 0.93, 0.44 and 0.94 respectively. Evidence for discriminant validity of KSFS comes from the results that the mean scores of schizophrenic patients were significantly higher than those of normal controls. Construct validity was assessed by calculating the 7 inter-areas correlations of the KSFS, and all areas were statistically significant. Significant correlations between the total scores of KSFS and those of SOFAS lend support for the concurrent validity of this instrument. Factor analyses were performed and two factors were extracted accounting for 63.7% of the variance. Sensitivity was assessed indirectly via the distribution and range of scores on the SFS. The normal control group showed a distribution around a higher mean with a moderate positive skew. Conclusion : KSFS was found to be a valid, reliable, and sensitive instrument which can be used to evaluate the degree of social functioning in the patients with schizophrenia.