Background: The objective of this study was to validate the Impact of a Child with Congenital Anomalies on Parents (ICCAP) questionnaire. ICCAP was newly designed to assess the impact of giving birth to a child with severe anatomical congenital anomalies (CA) on parental quality of life as a result of early stress. Methods: At 6 weeks and 6 months after birth, mothers and fathers of 100 children with severe CA were asked to complete the ICCAP questionnaire and the SF36. The ICCAP questionnaire measures six domains: contact with caregivers, social network, partner relationship, state of mind, child acceptance, and fears and anxiety. Reliability (i.e. internal consistency and test-retest) and validity were tested and the ICCAP was compared to the SF-36. Results: Confirmatory factor analysis resulted in 6 six a priori constructed subscales covering different psychological and social domains of parental quality of life as a result of early stress. Reliability estimates (congeneric approach) ranged from .49 to.92. Positive correlations with SF36 scales ranging from .34 to .77 confirmed congruent validity. Correlations between ICCAP subscales and children's biographic characteristics, primary CA, and medical care as well as parental biographic and demographic variables ranged from -.23 to .58 and thus indicated known-group validity of the instrument. Over time both mothers and fathers showed changes on subscales (Cohen's d varied from .07 to .49), while the test-retest reliability estimates varied from .42 to .91. Conclusion: The ICCAP is a reliable and valid instrument for clinical practice. It enables early signaling of parental quality of life as a result of early stress, and thus early intervention.