The current situation in India reflects significant contrasts, shaped by rapid industrialisation and rural-to-urban migration in search of better opportunities, alongside uneven wealth distribution. Despite India’s economic growth and development, a considerable proportion of the world’s undernourished children still reside in the country. Our research examines child malnutrition patterns in urban India’s poor and non-poor populations across two time periods: 2015–16 and 2019–21. We analysed cross-sectional data from the National Family Health Survey’s (NFHS) fourth and fifth rounds. Using concentration indices and binary logistic regression, we assessed key child health indicators across India: stunting, underweight, fever, and diarrhoea. Our analysis demonstrates that children under five years from economically disadvantaged states, particularly Bihar, Odisha, and Madhya Pradesh, face higher risks of undernutrition and morbidity in urban areas. These outcomes arise from poor living conditions, insufficient healthcare access, compromised maternal health, and low levels of parental education in these communities. The evidence suggests that improving public services, fundamental healthcare access and educational opportunities for urban poor mothers may help reduce poverty’s impact on child undernutrition.