Severe combined immunodeficiency (SCID) and other profound T- and B-cell lymphopenias are life-threatening conditions that benefit from early diagnosis and treatment. In October 2022, Ukraine launched a nationwide newborn screening (NBS) program for SCID using the T-cell receptor excision circle/kappa-deleting recombination excision circle/spinal muscular atrophy (TREC/KREC/SMA) assay, despite ongoing war-related challenges. The aim of this study was to analyze the results of the SCID NBS program in Ukraine, evaluate its effectiveness, and outline the current challenges and future directions for its development.