Introduction: In response to the COVID-19 pandemic, restrictions were imposed on various activities including nutritional services. This study was conducted with the objective to explore the status of the nutritional services and to identify the hardship and barriers faced by the vulnerable population and challenges for service providers and program managers during the initial phase of pandemic. Materials and Methods: A community-based cross-sectional qualitative study was conducted among three vulnerable population groups (slum dwellers, tribal population, and residents of disaster-prone area) in three districts of West Bengal, the reference period being April–September 2020. To assess the status of nutritional services and identify existing barriers or challenges, the study employed a mixed-methods approach utilizing focus group discussions (FGDs) as well as in-depth interviews (IDIs) conducted with beneficiaries, service providers and program managers. One habitation in each district was selected to obtain case scenarios on food insecurity and hardship. Descriptive analysis of household surveys and thematic analysis of FGDs and IDIs were done, and the findings were triangulated. Results: Different nutritional services (supplementary nutrition, micronutrient supplementation, growth monitoring, nutrition counseling, and nutrition rehabilitation) were disrupted. Shifting from hot-cooked meals to dry take-home ration was the most conspicuous change during restoration phase. Food security was absent in majority of the households. Reduction of income affected their affordability, which along with difficult accessibility to diverse food items contributed to their hardship. Service providers identified several challenges, including increased workload due to both COVID-19 activities and a rise in beneficiaries, transportation difficulties, and experiences of stigma and discrimination. Long administrative decision-making process, additional hurdles due to cyclone, and containment zones were identified as challenges by the program managers. Conclusion: As the hardship of vulnerable population was pervasive, it is necessary to formulate mitigating measures in light of the identified challenges and to combat similar crises in future.