Objective: Experiences of mothers of infants undergoing complex heart surgery were explored to build evidence-based family-centered interventions. Background: Congenital heart disease is the most frequent birth defect in the United States and is common worldwide. Methods: Eight mothers recalled through journal entries their experiences of the days before, during, and after their infant's surgery and shared advice for other mothers. Colaizzi's phenomenological method was utilized for data analysis. A validation survey of seven additional mothers from a support group occurred via email. Results: Six themes were identified and validated: Feeling Intense Fluctuating Emotion; Navigating the Medical World; Dealing with the Unknown; Facing the Possibility of My Baby Dying, Finding Meaning and Spiritual Connection, and the umbrella theme of Mothering Through It All. Conclusions: Through a clearer understanding of experiences as described by mothers, health-care providers may gain insight as to how to better support mothers of infants undergoing heart surgery. © 2013 Elsevier Inc.