This study was conducted to identify the factors that influence the level of adaptation of older Korean adults to skilled nursing facilities. The subjects were 500 adults aged 65 or older who were living in six different skilled nursing facilities in Seoul and Gyeong-gi-do, South Korea. The measures were a demographic form, Health Self-Rating Scale, Activities of Daily Living Scale, Self-Efficacy Instrument, Korean Simple Depression Scale, Quality of the Facility Scale and Facility Adaptation Scale. The analyses showed that the prediction model was significant (F = 128.624, P < 0.001). The value of the adjusted R2 was 0.435, which corresponds to the explanatory power of 43.5%. The factor that was found to have the greatest influence on the adaptation of older Korean adults to skilled nursing facilities was activities of daily living (β = −0.564), followed by self-efficacy (β = 0.321), quality of the facility (β = 0.164), depression (β = 0.133), decision to enter a skilled nursing facility (β = 0.122), perceived health status (β = 0.064) and age (β = −0.010). This cross-sectional study provides preliminary evidence that the level of adaptation of older Korean adults to skilled nursing facilities is related to their activities of daily living, self-efficacy, depression, decision to enter a skilled nursing facility, perceived health status and age, and to the quality of the facility.