In a foster care sample, the moderating effect of temperamental shyness on the association between parental sensitivity and attachment quality was tested. The foster parents of 59 foster children (age M=57 months, SD=16.4) filled out the Child Behavior Questionnaire. To control for confounds, symptoms of inhibited and disinhibited disordered attachment were derived from the Disturbances of Attachment Interview. The Strange Situation Procedure as well as a 15 minute parent-child interaction task were administered. Analyses indicated an interaction effect between parental perceptions of shyness and parental sensitivity for attachment quality. Shy children who had more sensitive foster parents were more often securely attached. For less shy children, no differences in attachment security were found in relation to the foster parents' sensitivity. These results are partially consistent with the differential susceptibility hypothesis. Shy children may benefit more from more sensitive foster parents when entering foster care. © 2012 Taylor & Francis.