Infrared spectroscopy, including both near-infrared (NIR) and mid-infrared (MIR) modalities, is emerging as a powerful, non-invasive tool for real-time organ viability assessment in transplantation. NIR spectroscopy has been applied to monitor perfusion and oxygenation in kidney and liver grafts during surgery and preservation, with studies showing strong correlations between spectral features and clinical viability markers such as Doppler indices or histological fibrosis. MIR techniques, like ATR-FTIR and microspectroscopy, offer chemically specific insights—especially in quantifying liver steatosis and fibrosis—enabling rapid, point-of-care evaluation of donor organs. Despite promising results, current applications are largely experimental, with challenges including tissue heterogeneity, limited depth penetration, and the need for standardization and clinical validation. Integrating IR spectroscopy into perfusion systems and surgical workflows may ultimately enhance decision-making and expand the donor pool by enabling more precise, objective viability scoring.