OBJECTIVES: To compare the efficacy and thermal response to treatment of nifedipine sustained release (nifedipine SR) with ginkgo biloba extract (ginkgo) with Raynaud disease (RD) by skin surface thermal pattern using digital infrared thermographic imaging (DITI). METHODS: This was a sub-analysis of Korean Raynaud (KOARA) study, the randomized flexible dose and open clinical trial to compare nifedipine SR with ginkgo. Total 76 RD patients were screened, and 52 patients were assigned randomly. Patients received RD management drugs for 8 weeks of either nifedipine SR or Ginkgo. DITI measurements were taken twice before and after 8 weeks medication. We compared the thermal reduction rate using cold challenge test (10°C, 2 minutes) and recovery rate at 30 minutes later after the challenge test between before and after 8weeks medication in both groups. RESULTS: The thermal reductions were shown in all RD patients of both groups and the thermal recovery rate at 30 minutes after cold challenge test were 24% in nifedipine SR group and 23% in ginkgo group before treatment. After 8 weeks treatment, the thermal reduction rate in nifedipine SR group was 79% and the rate in ginkgo group was 94%, but the difference between two groups was not statistically significant. The recovery rate at 30minutes after cold challenge in nifedipine SR group was 71% but the rate in ginkgo was 39% (p=0.02). CONCLUSIONS: This study shows nifedipine SR was more effective than ginkgo to prevent the thermal reduction in 8 weeks RD treatment. This result was consistent with the main KOARA study analysis.