This study investigated sleep, behavioral and emotional problems, and parental relationships and psychological distress in a group of school-aged children with bedtime problems and persistent cosleeping, compared to solitary sleepers and controls. Participants were 148 school-aged children with bedtime problems (44 cosleepers, 104 solitary sleepers) and 228 healthy peers. Results suggested that cosleepers have a significantly later bedtime, shorter nighttime sleep duration, higher Children's Sleep Habits Questionnaire (CSHQ) bedtime resistance and sleep anxiety scores, and more behavioral and emotional problems compared to other groups. Parents of cosleepers have a significantly higher level of psychological and couple distress. A past history of sleep problems, couple and maternal distress, CSHQ bedtime resistance, sleep anxiety, and night wakings subscale scores, and nighttime fears were significantly predictive of cosleeping. Thus, when cosleeping is present, the child's emotional adjustment, family relationships, and parental psychological problems should be investigated.