This study was designed to compare the nurse and nurses aids on their perception and performance levels for nosocomial infection control and to evaluate the relevant variables. The study data were obtained from 246 nurses and 219 nurse aids working at two university hospitals in Seoul, by using a constructed questionnaire. The data was collected from March to April of 1998, and analyzed using the SAS program for t-test, two way ANOVA, Pearson's Correlation Coefficients. The results were as follows; 1. The mean score of the perception level for nosocomial infection control of the nurse(M= 4.72) was higher than that of the nurses aids(M= 4.56). 2. No significant association was found between the nurse and nurses aids on their performance level for nosocomial infection control. 3. The score of perception level showed significant interaction by age in all domains, by career in contaminated material and environmental management, and by department in sterile and environmental management. Regarding the performance levels, the score showed significant association between hand washing and clothing management by age and career. However, there was no significant difference by department. 4. A positive correlation was found in the perception and performance levels for nosocomial infection control between the nurse and nurse aids. In conclusion: the mean score of the perception level for nosocomial infection control in nurses was higher than that of their performance level. In the case of nurses aids, the mean scores of the perception and performance level for the nosocomial infection control were the same but lower than those of the nurses. It is suggested that appropriate hospital infection control programs should be developed by continuous systemic education and practice to improve the nurse and nurses aids' level of perception and performance for nosocomial infection control.