The current meta-analysis examines the links between unresolved representations of attachment, anomalous parental behavior, and disorganized attachment relationships in 12 studies including 851 families. We found moderate effect sizes for the associations between unresolved states of mind and anomalous behavior (r = .26), unresolved states of mind and infant disorganized attachment relationships (r = .21), and anomalous behavior and disorganized attachment relationships (r = .34). Sample characteristics, observational context, and observational measure were not associated with differences in effect sizes. Only a small part of the association between unresolved states of mind and disorganized attachment relationships was explained by the mediation of anomalous parental behavior (.26* .34 = .09). Other factors yet to be uncovered must mediate the influence of unresolved states of mind on infant disorganized attachment; thus, further exploration of infant, parental, ecological, and genetic factors are warranted.