Background: Children are exposed to flame retardants from the built environment. Brominated diphenyl ethers (BDE) and organophosphate-based flame retardants (OPFRs) are associated with poorer neurocognitive functioning in children. Less is known, however, about the association between these classes of compounds and children's emotional and social behaviors. The objective of this study was to determine if flame retardant exposure was associated with measurable differences in social behaviors among children ages 3-5 years. Methods: We examined teacher-rated social behaviors measured using the Social Skills Improvement Rating Scale (SSIS) and personal exposure to flame retardants in children aged 3-5 years who attended preschool (n = 72). Silicone passive samplers worn for 7 days were used to assess personal exposure to 41 compounds using gas chromatography-mass spectrophotometer. These concentrations were then summed into total BDE and total OPFR exposure prior to natural log transformation. Separate generalized additive models were used to evaluate the relationship between seven subscales of the SSIS and lnSBDE or lnSOPFR adjusting for other age, sex, adverse social experiences, and family context. Results: All children were exposed to a mixture of flame retardant compounds. We observed a dose dependent relationship between ln Sigma OPFR and two subscales where children with higher exposures were rated by their preschool teachers as having less responsible behavior (p = 0.07) and more externalizing behavior problems ( p = 0.03). Additionally, children with higher ln Sigma BDE exposure were rated by teachers as less assertive (p= 0.007). Conclusions: We observed a cross-sectional association between children's exposure to flame retardant compounds and teacher-rated social behaviors among preschool-aged children. Children with higher flame retardant exposures exhibited poorer social skills in three domains that play an important role in a child's ability to succeed academically and socially.