In this study we seek to better understand the experience of children exposed to parental negative conditional regard (NCR), a parenting practice where parents’ emotional availability is contingent on behavioral compliance rather than provided unconditionally. We propose that children parented with greater levels of NCR will show stronger negative reactions (i.e., physiological, subjective appraisal) to situations involving the expression of vulnerability than those parented with lesser levels of NCR, as the former will lack primary regulation strategies (e.g., asking for help), making vulnerability harder to resolve. We expect these children will display stronger reactions to situations involving expressing vulnerability to caregivers as they may fear rejection, after controlling for their responses to vulnerability alone. With a diverse sample of school-aged children (N = 109, 8–12 years of age), we test whether NCR, measured using parent- and child-reports, is associated with children’s negative reactions to hypothetical situations where 1) attachment needs are evoked (experience-only vignettes) and 2) attachment needs are evoked and vulnerability is expressed through help-seeking (HS vignettes). Children’s RSA profiles and subjective appraisals of hypothetical children were collected in a standardized laboratory paradigm. Results indicate that while parent-reported greater caregiver use of NCR was not significantly associated with physiology or appraisals, child-reported NCR was significantly associated with lower RSA and more negative appraisals of the hypothetical child when expressing vulnerability to the caregiver (HS vignettes). Implications of these findings are discussed in terms of attachment theory in middle childhood.