PURPOSE: The purpose of this study was to observe the success rate, the average of total admininstration doses and the complications associated with a convenient method of adenosine administration for paroxysmal supraventricular tachycardia (PSVT). METHODS: A non-blind, randomized, prospective study was conducted during the 30 months from January 1999 to June 2001. We enrolled 65 cases during this period. The number of cases in the standard method group was 35, and that in the mixed method group was 30. In the standard method group, 6 mg of adenosine was administered intravenously; therefore, 15~20 ml of normal saline was immediately flushed. This method is usually used and recommended. In the mixed method group, 6 mg of adenosine had been previously mixed with 15 ml of normal saline was administered intravenously without any additional manipulation. We evaluated the success rate, the average successful doses, and the complications of each group. RESULTS: The success rate was 80% in the standard method group and 85.7 % in the mixed method group, but this difference was not statistically significant (Chi square test, p=0.39). The average of total admininstration doses were 10.3+/-6.3 mg in the standard method group and 11.0+/-6.5 mg in the mixed method group, but this difference is not statistically significant (student t-test, p=0.07). There was no remarkable complication in the mixed method group. CONCLUSION: The mixed method was effective and more convenient than the standard method. A further, larger study is required.