This study assessed the links between infant negative affect, parental reflective functioning (RF), and toddler behavior problems in a sample of 84 women and their infants. Mothers provided self-report demographic data and completed the Infant Behavior Questionnaire-Revised during a home visit when the infant was 7 months old. They also completed the Child Behavior Checklist over the phone when their infant was 18 months old. During a lab visit when their infant was 16 months old, mothers participated in the Parent Development Interview-Revised Short Form, which was coded for RF. Results suggest that parental RF was not associated with infant negative affect or toddler behavior problems. However, infant negative affect correlated positively with toddler behavior problems and both correlated with cumulative sociodemographic risk. Results of a moderation analysis revealed that RF moderated the relationship between infant negative affect and toddler behavior problems, such that when parental RF was high there was a nonsignificant relationship between infant negative affect and toddler behavior problems.