OBJECTIVES To compare the efficacy and safety of a nifedipine sustained release (nifedipine SR), with ginkgo biloba extract as treatment for primary Raynaud's phenomenon in Korean. METHODS ; Multi-centred, randomised, flexible dose and open study. A total of 134 patients with primary Raynaud's phenomenon were selected from 3 centers and randomly assigned to either the Nifedipine SR group (Group N) or the Ginkgo biloba extract group (Group G) in the ratio of 2:1. After a run-in period of two weeks, participants received treatment for eight weeks. Primary efficacy evaluation was any percent change of the Raynaud attack rate between the reference value before treatment and after the 8-week treatment. A safety was also evaluated. RESULTS ; Out of 134 patients with primary Raynaud's phenomenon, 39 subjects dropped out of the program during the selection period. Ninety-three subjects (70.5% of the original pool) were randomly assigned, and 64 subjects (Group N: 42, Group G: 22) among the 93 completed this clinical trial. There were 24 male subjects (25.81%) and 69 female subjects(74.19%), and the average age of the subjects was 39.20 (Group N: 37.67, Group G: 42.13). The percent change of the attack rate in Intention To Treat (ITT) group was 50.05% at 7 and 8 weeks after treatment in Group N, while it was just 31.02% in Group G (p-value=0.03). The improvement was shown to be much higher in Group N than in Group G. No difference in QOL items was found between the two groups in this clinical trial. No significant adverse events occurred; severity of the adverse events incurred was mostly mild, and those adverse events were improved without specific treatment. CONCLUSIONS Nifedipine SR was more effective pharmacotherapy than Ginkgo biloba for primary Raynaud's phenomenon (Percent change of R : 50.1% vs. 31%). Both Nifedipine SR and Ginkgo biloba showed tolerability without serious adverse events.