An important tenet of attachment theory is that classification of security or insecurity as derived from the Strange Situation reflects the quality of an infant's relationship with its caregiver. One piece of evidence supporting this claim is the lack of concordance of classification between an infant and its mother and father. We performed a meta-analysis of the 11 studies that have examined the concordance of mother/father attachment to an infant. We found that security of attachment to one parent was dependent upon security to the other parent, that type of insecurity (avoidant/resistant) to one parent was dependent upon type of insecurity to the other, and that subcategory classification within the secure category (B1B2/B3B4) to one parent was dependent upon subcategory classification to the other. These data raise important questions regarding the meaning of infant attachment classification as derived from the Strange Situation. Among the possible explanations for the pattern of data are existence of concordant parenting styles and/or influence of infant temperament (possibly the tendency to cry upon separation) on classification of security/insecurity in the Strange Situation.