PURPOSE: To collect and interpret basic data involving the discomfort level of platelet donors and to see which nursing interventions would help make plateletpheresis more comfortable. METHODS: Using " the Platelet Donor's Discomfort Scale" developed by the researcher herself and reviewed by an expert panel, the severity of discomfort as well as factors contributing to the development of this discomfort were analyzed. This scale contained 59 items and each item was scored by the 4-point Likert manner. Between March 1, 1996 and May 31, 1996, 500 platelet donors(16 years of age and older) were enrolled in this study. The Statistical methods used were factor analysis, t-test, and ANOVA. The results were as follows : 1. The mean of the platelet donor's discomfort scale was 130, range 69-207, possible score ranging from 59-236. 2. The platelet donor's discomfort scale had psychological, environmental, physical, and time-related factors. The time-related factor was the highest positive correlation with the development of the discomfort. 3. In looking at the psychological and environmental factors of the discomfort scores, the 16-20 age group had significantly higher rating than those of the 26-30 age group. The students' group had higher scores than the soldier's group, and those who used the V-50, MCS-3P, or the PCS Plus machines had higher scores than those who used the COBE Spectra machine(P<.05, respectively) 4. In relation to the physical factor of the discomfort score, the youngest group felt significantly more discomfort, the student's group had a higher score than the soldier's group had a higher score than the soldier's group, and those who used the V-50, MCS-3P, or the PCS Plus machines had higher scores than those who used the COBE Spectra machine(P<0.05, respectively). 5. The time related factor of the discomfort score had the highest scores in every variable, how ever, statistically significant differences were no found between any of the variables(P>.05). CONCLUSION: Based on the above results, it can be oserved that the time-related factor was the most important factor influencing discomfort. The age and job of the donor, as well as the type of machine used, were significant variables in predicting the level of discomfort, regardless of psychological, environmental, and physical factors. This data could be used to determine nursing interventions that would relieve some of the discomfort of patients, as well as donors, undergoing plateletpheresis. Furthermore, consideration of the donor's time, introduction of a platelet donor pool system, publicity and education about platelet donation are required.