Diphtheria remains a significant public health concern in India despite the availability of routine immunization. This survey-based review analyzes national surveillance data (2020–2024), WHO–UNICEF immunization reports, and responses from frontline healthcare workers to assess the current trends, antitoxin accessibility, and challenges in early diagnosis. Findings indicate a shift in disease burden from young children to adolescents and young adults, mainly due to waning immunity and low booster-dose coverage. Limited availability of Diphtheria Antitoxin (DAT), delays in procurement, and cold-chain constraints continue to affect timely case management across several states. Early diagnosis also remains difficult because initial symptoms resemble common upper respiratory infections, primary-care staff have limited training, and rapid diagnostic tools are not uniformly available. Overall, the survey highlights an urgent need for improved booster-dose coverage, decentralized DAT stock management, and stronger early-detection systems to reduce diphtheria-related morbidity and mortality in India.