This study provides information on how to improve the wearing sensation and the fit of slim-fit jeans through an analysis of actual wearing conditions and dissatisfaction. The study is based on a questionnaire survey. A survey was conducted on 296 women in their 20s living in Korea to analyze wearing dissatisfaction with slim-fit jeans. The study used descriptive statistics for analysis using SPSS Statistics Ver.23. Surveys on the actual situation of wearing jeans and level of dissatisfaction indicated that most women in their 20s mainly wore slim-fit jeans and were aware of the size of their jeans. Most tended to double-check the size of the jeans, indicating that the inaccurate sizing system of slim-fit jeans caused confusion for consumers. In addition, the results of the survey on the most considered parts of the body when consumers buy jeans are waist, thigh and leg length. They insisted that their waists were thin and their thighs were thicker than their waists; so their pants would not fit and they were obese. There is a problem between waist size and thigh size; therefore, it is necessary to develop new patterns for slim-fit jeans with improved fit around the waist area that can improve the negative results of surveys on the level of dissatisfaction, indicating discomfort in the waist, belly, and thigh areas while wearing slim-fit jeans.