Purpose: Ongoing armed conflicts, like the one in Colombia, have forcibly displaced millions of people including many young children. This study aimed to assess the mental health of internally displaced preschoolers in Bogotá Colombia and to identify correlates of mental health in these children. Methods: Cross-sectional study conducted among 279 children attending four kindergartens in a deprived neighbourhood in Bogotá. Child mental health was assessed with the Child Behaviour Checklist (CBCL) 1.5-5 years, a parent-report. Univariate analyses and multivariate logistic regressions were performed to assess the association between displacement and child mental health and to identify correlates of mental health in displaced children. Results: Displaced children (n = 90) more often met borderline cut-off scores for the CBCL scales than non-displaced children (n = 189) (e.g. total problems 46.7 vs. 22.8 %; p < 0.001). The association between displacement and presence of CBCL total problems remained after adjustment for socio-demographic factors (Adjusted OR 3.3, 95 % CI 1.5; 6.9). Caretaker's mental health partly explained the association. In displaced children, caretaker's mental health (p < 0.01) and family functioning (p < 0.01) were independently associated with child mental health. Exposure to traumatic events and social support was also associated with child mental health; however, associations were not independent. Conclusion: In this deprived neighbourhood in Bogotá, preschool children registered as internally displaced presented worse mental health than non-displaced peers. Family functioning and caretaker's mental health were strongly and independently associated with displaced children's mental health.