Introduction: Behavioral sleep interventions (BSIs) improve infant sleep but are less implemented in Asian countries, where co-sleeping is common. This study explored environmental (sleep arrangements) and personal (parental cognition) barriers to BSI implementation among South Korea parents. Methods: A total of 507 parents with children aged 6 to 36 months. Participants completed the Parental Understanding and Misperceptions about Baby’s sleep- Questionnaire (PUMBA-Q) and Brief Infant Sleep Questionnaire-Revised (BISQ-R). Information about sleep arrangements and BSIs experience were collected. Path analysis tested a model predicting BSIs implementation and infant sleep. Results: Only 21.9% of parents reported implementing at least one BSIs. Children receiving BSIs had significantly longer total sleep. Path analysis showed parental cognition and bed-sharing directly affected BSIs and indirectly affected child sleep through BSIs implementation. Discussion & Conclusion: This study identifies sleep arrangement and parental cognition as barriers to implementing BSIs, which may inform tailored BSI strategies.