The purpose of this study was to examine nurses' perceptions of medication treatment for psychiatric patients and to compare these perceptions with the perceptions held by the patients. The methodology used in this study was a descriptive design with semi-structured and open-ended interviews. This study used a convenience sample of 112 nurses who worked in, and 209 patients who were under psychiatric treatment, in four hospitals attached to a university and one national mental hospital in the city of Seoul. The collected data were analyzed by SAS, using percentages for descriptive purposes, and t-test or x2 for comparing the variables. The results were as follows: 1. There was no significant differences between nurses' and patients' perceptions on the extent to which patients complied with their medication treatment. Generally speaking, the mean compliance scores for both nurses and patients was high (nurse: x=3.70, Patient: x=3.76). 2. There was a significant difference in nurses' and patients' perceptions on the reasons why patients do not take medication. The nurse group indicated that the patients did not take medication because of the "worry about side effects or habitu-ation(49.53%)", "boredom from long-term use of medication(26.17%)" and "distrust toward medical staff (12.15%)", but the patient group indicated that they "did not want to be dependent on medication (25%)", "forgot to take medication(19.7%) and "worried about side effects or habituation( 15.91%). 3. As for the necessity of medication, both groups showed some different responses. Even though both groups were aware of the necessity of taking medication, the patient group(21.53%) showed a more negative response. As for the effects of medication, both groups (nurses and patients) showed positive responses. However, the nurse group showed a higher positive response(91.07%) than the patient group(74.16%). 5. Both the patient and nurse group indicated that the most helpful element for the patient's life under psychiatric treatment was interviews and conversations with therapists and nurses. However, the nurse group showed a higher response (70.15%) than the patients group(47.15%). According to the patient group, family support for the patient was another important factor for psychiatric treatment and daily struggles. In conclusion, as there were differences between the perception of nurses and patients, the nurse must consider the patients' subjective perceptions first. They should also revaluate their false belief and prejudice concerning the patients' perceptions. Such information can provide a base to be applied by the nurses in devloping effective mutual relationships with patients which can in turn help in compliance with medication regimen. As it was confirmed that medication was the most important factor in the patients' recovery, a thorough education program on the therapeutic effect of medication and the necessity of their continued use after discharge is also needed.