Young children who experience adversity are at increased risk for developing psychological difficulties across the lifespan. Among community samples, parent-child relationship dynamics interact with child effortful control to predict child behavior problems. The nature of these associations has not been examined among children who have experienced early childhood adversity and who may be particularly sensitive to familial effects on child development. To this end, this study examines if child effortful control moderates associations between parent-child relationship dynamics (i.e., cohesion, enmeshment, disengagement) and child behavior problems in early childhood. Participants in this multimethod (i.e., observational assessment, parent-report survey, semi-structured interview, child protection records) study included 274 preschool-aged children (M age = 50.86 months; 52% with documented case of moderate-severe maltreatment) and their primary caregivers assessed at two time-points spaced 6 months apart. Results indicated that for children low, but not high, in effortful control, greater parent-child cohesion was associated with fewer child behavior problems, and greater parent-child enmeshment was associated with greater child behavior problems. Children higher in effortful control demonstrated lower levels of behavior problems regardless of variation in parent-child cohesion or enmeshment.