Background: Although muscles and bones interact with each other through various secretory factors, the role of sclerostin, an osteocyte-secreted factor, on muscle metabolism has not been well studied. We investigated the levels of serum sclerostin in Korean olderadults with sarcopenia. Methods: Blood samples were collected from 129 participants who underwent evaluation of muscle mass and function in an outpatient geriatric clinic of a teaching hospital. Sarcopenia and related parameters were determined using cutoff values for the Asian population. Serum sclerostin levels were measured using an enzyme-linked immunosorbent assay. Results: The mean age of the participants was 69.6 years, and 20 participants (15.5%) were classified as having sarcopenia. Afteradjusting for age, sex, and body mass index, serum sclerostin levels were significantly lower in participants with sarcopenia, lowmuscle mass, or weak muscle strength (P=0.003 to 0.045). Serum sclerostin levels were positively associated with skeletal muscleindex and grip strength after adjusting for confounders (P=0.001 and P=0.003), whereas sarcopenic phenotype score showed a negative association (P=0.006). These increases in muscle mass and strength were also dose dependent as serum sclerostin levels increased (P for trends=0.003 and P for trends=0.015). Higher serum sclerostin levels were associated with lower odds ratio (ORs)for sarcopenia, low muscle mass, and weak muscle strength after adjusting for confounders (OR, 0.27 to 0.50; P<0.001 to 0.025). Conclusion: Higher serum sclerostin levels were associated with a lower risk of sarcopenia, low muscle mass, and weak musclestrength in Korean older adults.