Background: The nutritional and immunization status of children are crucial factors and also act the most vital part in determining the future health of a country. The aim of the study is to examine the immunisation and getting the knowledge of nutritional among under five children in Bangladesh and India. The study also focuses on exploring the differences between the current status of both countries. Method: Bangladesh Demographic Health Survey, 2022 and National Family Health Survey data, 2019–2021 of India datasets. The sample size is 30,375 residential households and 636,699 households in India in Bangladesh. The under-five children nutritional status is measured through standard indicators of anthropometric weight-for-age (WAZ)and height-for-age (HAZ). The study also focuses on polio, children’s immunization status, DPT, BCG and measles vaccinations. Regarding the status of child immunization, only polio, measles, BCG and DPT vaccinations are considered. Result: These findings of the results highlight the need for targeted policies, investments in infrastructure, and societal changes to promote gender equality and inclusive economic growth. By leveraging the lessons learned from each other’s experiences and fostering regional cooperation, India and Bangladesh can make significant strides toward improving socio-economic and demographic outcomes for all their citizens, particularly in the areas of child health and nutrition. Conclusion: The study concludes that under-five children are suffering from undernutrition in Bangladesh and India. Lower unemployment, high wealth index, and attainment of better educational of Bangladeshi mothers helps in maintaining better immune system and nutrition management of children. While Indians have to focus more on the immortalization and measurement of nourishment substitutes for the children as India is a developing country. Our findings help the Bangladesh governments and Indian to implement health policies which help in improve immunity system and the nourishment measurement of the children under-five.