Purpose: A low serum 25-hydroxyvitamin D [25(OH)D] level in the blood has been correlated with an increased risk of diabetes mellitus; however, the association betweenserum 25(OH)D level and insulin resistance has not been established in a Koreanrural population. The aim of this study was to investigate the independent associationbetween serum 25(OH)D level and insulin resistance in rural Korean adults. Materials and Methods: This study used data from the Korean Genome EpidemiologyStudy--Kangwha Study. In the 2011 study, 1200 adults completed health examinations. In an ancillary study, serum 25(OH)D level was measured in a subsample(n=813). After excluding those taking vitamin D supplements, a cross-sectional analysis was carried out on 807 participants (324 men and 483 women) aged 40 to 89 years old. Measured from overnight fasting blood samples, glucose and insulin levels were used to calculate the homeostasis model assessment for insulinresistance (HOMA-IR). Measures of glucose, insulin, and HOMA-IR were log-transformed for parametric tests. Results: Serum 25(OH)D level was inversely associated with HOMA-IR (β=-0.003, p=0.039) in a univariate analysis. However, the association was not significant after adjustment for sex and age (β=-0.002, p=0.123) or after adjustment for sex, age, body mass index, smoking status, alcoholintake, and regular exercise (β=-0.003, p=0.247). Conclusion: Our findings suggest that vitamin D is not independently associated with insulin resistance in Korean men and women.