The purpose of this study was to compare sleep disturbances of children and their mothers, children's behavioral problems, and parenting self-efficacy between Korean American families who coslept and those who did not cosleep. Forty-eight mothers of children between 3 and 8 years of age completed the following surveys: Children's Sleep Habits Questionnaire, Pediatric Symptom Checklist, Pittsburgh Sleep Quality Index, Parenting Self-Efficacy Questionnaire, and Acculturation Rating Scale for Mexican Americans II. Overall, 48% (n = 23) of families coslept, and families with younger children coslept more than families with older children (x2=12.48,p<.05). When the families were divided into non-cosleeping (i.e., rarely) and cosleeping (i.e., sometimes and usually) groups, 100% of the cosleeping children had sleep disturbances compared to 56% of the non-cosleeping children (x2=8.67,p<.01). For mothers, 28% (n = 7) of the non-cosleeping mothers reported sleep disturbances, compared to 52% (n = 12) of the cosleeping mothers (x2=2.93,p=.08). Children's behavioral problems were not different between the two groups (F = 1.78, p = NS). Cosleeping mothers reported lower parenting self-efficacy than non-cosleeping mothers (F = 6.26, p < .05). When providing care to Korean American families with young children, their cosleeping, sleep disturbances, and parenting self-efficacy need to be addressed.