This study was designed to identify the relation between the perceived family support and social adjustment of discharged patients with chronic mental illnesses. The subjects for this study were 50 patients with chronic mental illnesses receiving out-patient treatment at one general hospital and one private hospital in Seoul. The data were collected during the period from April 25, 1991 to May 27, 1991. The perceived family support was measured by the Family Support Scale developed by Hyun Sook Kang. A questionnaire which was developed by Weissman was modified by the author of this study to measure the Social Adjustment. The data were analyzed by descriptive statistics and Pearson Correlation Coefficients, using the SPSS program. The results of this study can be summarized as following ; 1) For the perceived family support, the mean was 2.63 points and the source of family support was almost always the mother. 2) For the social adjustment level, the mean was 2.63 points, and the results showed the best social adjustment was in the area of parental role and family adjustment, and the poorer adjustment was in the area of work and leisure. 3) The relationship between the perceived family support and social adjustment revealed a significant correlation.(r=.38, p<.05) Therefore the hypothesis "the higher the level of perceived family support, the higher the social adjustment level" was accepted. In conclusion, the study revealed that family support is an important factor related to the social adjustment level in patients with chronic mental illnesses.