Study objectives: Early life determinants of sleep problems are mostly unknown. The first 1000 days of life (ie, the time between conception and a child's second birthday) is a period where the foundations for optimum health, growth and neurodevelopment are established. The aim of this explorative study is to identify potential early life determinants of sleep problems at age 7–8 years. Methods: Data from the Amsterdam Born Children and their Development cohort study (n = 2746) were analyzed. Sleep problems at age 7–8 years were reported by the caregiver in the ‘Child Sleep Habits Questionnaire’. A higher total score indicates more sleep problems. After multiple imputation (n = 20), we studied multivariable associations between all potential determinants and sleep problems using regression analysis. Results: A higher pre-pregnancy body mass index (BMI) was associated with more sleep problems at age 7–8 years [β 0.12 (95% CI 0.05, 0.18)]. Children of mothers with symptoms of anxiety during pregnancy [β 0.06 (95% CI 0.03, 0.09)] and infancy period [β 0.04 (95% CI 0.00, 0.07)] had more sleep problems. Children of mothers drinking ≥1 glass of alcohol a day around 14 weeks of gestation had a 2 points higher sleep problem score [β 2.55 (95% CI 0.21, 4.89)] and children of mothers smoking ≥1 cigarette per day in that period had a one point higher score [β 1.07 (95% CI 0.10, 2.03)]. Infants with relative weight loss (delta BMI-SD) had a higher sleep problem score during childhood [β −0.32 (95%CI -0.60, −0.04)]. Conclusions: We identified several potential determinants during pregnancy and infancy associated with childhood sleeping problems. We encourage further research into these and other potential determinants to replicate results and to identify underlying mechanisms.