Sleep is essential for children´s emotional and cognitive wellbeing. Different sleep variables (sleep-wake characteristics/habits/disorders) are associated to Internalizing and Externalizing problems.

to analyse parent´s perception about different sleep variables and Internalizing and Externalizing behavior problems, in a sample of Portuguese school children, exploring associations between these variables.

100 parents/legal representatives of children (range = six to eleven years old) filled in a sociodemographic questionnaire, the Sleep-Wake Children Questionnaire and the Child Behavior Checklist 6-18 (CBCL).

Most children took about ten minutes to fall asleep and did not wake up during the night. Some children were afraid of sleeping in the dark and needed the presence of a light (possible dyssomnia) and/or of a transitional object to fall asleep. During the night some children grind their teeth (possible parasomnia). The subscale with the higher T mean value was Isolation/Depression and the global dimension with the higher T mean value was Internalizing Problems. Most children had a 'normal” score in every CBCL subscales. Isolation/Depression presented more 'borderline” cases and Aggressive behaviours presented the highest number of children in the clinical category. The global dimension showing a higher number of clinical cases was Internalizing Problems. Generally, several sleep variables were significantly associated to behavior problems.

Several associations were found between sleep habits/problems and behavior problems, particularly Internalizing problems. It seems important to create prevention/intervention programs to educate parents on sleep and behavior, to improve sleep habits and reduce the presence of sleep and/or behavior problems.