This study examined ethnic differences in the relationship between cosleeping and sleep problems in the United States, taking socioeconomic status (SES) into consideration. The sample consisted of 186 urban families with a healthy 6- to- 48-month-old child and was grouped as follows: white lower SES (n = 40), white higher SES (n = 54), black lower SES (n = 43), and black higher SES (n = 47). Regular cosleeping was associated with increased night waking and/or bedtime protests among lower SES white children and higher SES black children. Among families who coslept, white parents were more likely than black parents to consider their child's sleep behavior to be a problem, i.e., stressful, conflictual, or upsetting as well as regularly occurring. One explanation is that differing childrearing attitudes and expectations influenced how parents interpreted their children's sleep behavior.