Ultra-rapid genomic sequencing (urGS) is increasingly used in neonatal and pediatric intensive care settings (NICU/PICU), demonstrating high diagnostic and clinical utility. This study aimed to explore the perspectives of healthcare professionals (HPs) and the challenges raised by urGS, particularly when making treatment decisions. Four focus groups and two interviews were conducted with HPs who had experience using urGS in NICU/PICU. Inductive content analysis was used to analyze the data. Nineteen HPs participated overall (eight clinical geneticists, nine genetic counselors, and two intensivists). One challenging area of practice identified by HPs was setting realistic expectations for outcomes of urGS among HPs and families. HPs reported modifying pre-test counseling to include life-limiting diagnoses as a possible test outcome and felt concerned about the timing of the test and its impact on parent–child bonding. UrGS results of uncertain prognostic significance posed considerable challenges. Moral distress arose when families and HPs were misaligned regarding treatment goals following the urGS diagnosis. We identified areas of practice that remain ethically challenging for HPs using urGS in the NICU/PICU. HPs experiences of using urGS in the NICU/PICU could inform specialized training in withdrawal of treatment decision making for the genomics workforce.